Determining the gender of your baby/fetus during pregnancy | Boy/Girl
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Mom wants to know most
Baby/fetus gender during pregnancy
Is my child a boy or a girl?
"Is the baby in my belly a boy or a girl?"
It's a natural feeling that arises in a mother's heart from the moment she finds out she's pregnant.
Small palms, soft cheeks...
What kind of face will this child have when born?
The questions that arise along with these loving feelings,
From my 15 years of experience as an obstetrician and gynecologist, having looked after over 3,000 mothers and babies
We will solve everything.
-Can you really tell if you have a baby nub at 12 weeks pregnant?
・The ultrasound said it was a boy, but is that certain?
-Is it true that if you have severe morning sickness, you're having a girl?
-Can we trust that NIPT is 99% accurate?
Knowing the answers to these questions
"I see, so that's why you find out at this time."
"I see, so that's the reason."
With this new discovery,
Your love for your baby in the womb will grow even stronger.
Once you know the gender, you can imagine your baby more specifically.
"What name should we give this child?"
"What clothes should I dress you in?"
"What kind of room should I make for you?"
Enjoy such happy times with the right knowledge
So that you can spend your time with peace of mind
I will tell you with all my heart.
When can gender be determined during pregnancy?
Accuracy of judgment by week and latest situation
The crucial difference between 14-week vs. 20-week ultrasounds
The best timing as advised by an obstetrician-gynecologist
At what week of pregnancy can you find out the gender of your baby?
This is one of the most frequently asked questions during prenatal visits.
In fact, there are two types of timing for determining the sex: "when it is technically possible" and "when it is technically possible."
Did you know that there are two periods when it can be determined with certainty ?
Let me start with a startling fact.
A baby's gender is determined the moment the sperm and egg are fertilized.
In men, there are sperm that carry an X chromosome and sperm that carry a Y chromosome.
Whichever fertilizes the egg (X chromosome) determines the sex.
However, before we can confirm that determined gender,
You have to wait until your baby's external genitalia have developed.
[Possibilities for determining gender by pregnancy week]
7-10 weeks of pregnancy: impossible to determine
During this period, the protrusions of the external genitalia (genital tubers) themselves do not show up on the ultrasound.
It is completely impossible to distinguish between men and women.
11-13 weeks pregnant: Predictable with BabyNab (60-70% accuracy)
The much talked about "baby nub theory" allows for early gender prediction.
However, at this stage, the external genitalia of men and women are still similar in shape,
There are limits to certainty.
14-15 weeks pregnant: Possible to determine whether the baby is a boy (80-85% accuracy)
In boys, the external genitalia become clearly visible.
They can often be identified as being "peanut-shaped."
17-18 weeks pregnant: Can determine whether the baby is a girl (85-90% accuracy)
In girls, the three lines of the external genitalia (the folds of the labia minora)
You will be able to see it as a leaf-like shape.
After 20 weeks of pregnancy: High accuracy (95% or higher) for both men and women
At this stage, the external genitalia are fully developed,
The chance of a false positive is greatly reduced.
So why do boys find out earlier?
The reason for this is the influence of the male hormone testosterone .
For boys, testosterone secretion begins around the eighth week of pregnancy.
The external genitalia protrusions grow aggressively.
On the other hand, in the case of girls, the protrusion does not grow,
To make sure there are no protrusions
It takes more time.
"At 14 weeks they told me it was a boy, but later it turned out to be a girl."
Have you ever heard of an experience like this?
This is not at all uncommon.
During the first trimester, girls may also experience temporary bump-like structures.
Even experienced obstetricians can have difficulty making a diagnosis.
When I tell pregnant women the gender,
Always say, "Based on the current findings, there is a high possibility that ____ is the case,
It's not definitive," he said.
This is because the accuracy of gender determination improves as the baby grows .
The accuracy of the assessment also depends heavily on the following factors:
・Baby's position (legs closed, back facing, etc.)
- The position of the umbilical cord (which may obscure the external genitalia)
- Amount of amniotic fluid (hard to see if there is oligohydramnios)
- Maternal BMI (if the mother is obese, the image may be blurred)
- Performance of the echo device (higher resolution allows for more accurate results)
Therefore, instead of thinking that "we can know for sure with one test,"
"It becomes more certain as the pregnancy progresses."
The correct understanding is to think of it this way.
The popular baby nub gender determination method
Scientific basis for 70-90% accuracy and how to distinguish
Can you tell at 12 weeks pregnant? The 30-degree angle rule and
The true feelings of obstetricians and gynecologists revealed
"We found out the gender through the baby nub!"
"I'm only 12 weeks pregnant and I already know it's a boy!"
I saw this post on social media,
Many pregnant women may be wondering, "What exactly is a baby nub?"
Baby nub literally means "baby's small protrusion."
Medically known as the "genital tubercle"
This is the part that will become the baby's external genitalia.
By looking at the angle and shape of this small protrusion,
Gender can be predicted 7-10 weeks earlier than with regular prenatal checkups
It is attracting attention as a
But honestly, as an obstetrician-gynecologist...
"Baby nub is not a medically proven method of gender determination."
That is the reality.
Still, there's a reason why many pregnant women are interested in it.
[Three reasons why BabyNav is attracting attention]
1. Overwhelmingly early diagnosis
Compared to normal gender determination (around 20 weeks pregnant),
It may be possible to predict the weather up to two months earlier.
2. No additional costs
Since it can be determined using ultrasound images from regular prenatal checkups,
There is no special testing fee.
3. Entertainment
One of the joys of early pregnancy is
The whole family can enjoy making predictions.
Now, let's take a closer look at how to actually determine if you have a baby nub.
[The "30-degree rule" for determining baby nub]
With the baby lying on his side
The angle of the genital tubercle is measured using the spine as the reference line (0 degrees).
・Facing upward at an angle of 30 degrees or more → Possible sign of a boy
・Less than 30 degrees and close to horizontal → Possibly a girl
・Between 10-30 degrees → Difficult to judge (gray zone)
The number "30 degrees" actually has a medical basis.
For boys,
Around the eighth week of pregnancy, the genital tubercle begins to grow forward due to the influence of male hormones.
At 12-13 weeks of pregnancy, the part that will become the penis begins to grow.
It rises at an angle to the spine.
For girls,
Because it is not affected by male hormones, the genital tubercle does not grow forward,
Keep your spine roughly parallel to the ground.
But here's an important issue.
"At 12-13 weeks of pregnancy, the difference between boys and girls is still too subtle."
That is what it means.
According to overseas research data,
BabyNav's reported accuracy is as follows:
・11th week of pregnancy: about 60-65%
・12 weeks of pregnancy: about 70-75%
・13th week of pregnancy: about 80-90%
At first glance, this appears to be highly accurate, but there are some points to note.
[Limitations and points to note when determining baby nub status]
1. Highly dependent on image quality
The research uses high-resolution dedicated equipment,
There are limitations to the image quality of regular prenatal checkups.
2. Specialized skills are required
Accurate angle measurement requires considerable experience and skill.
It can be difficult for pregnant women to make a diagnosis on their own.
3. It depends on the baby's position
Accurate angle measurements cannot be made unless the camera is held horizontally.
There are many times when you can't get into the position you want.
4. There are individual differences
There are individual differences in the development of babies.
Sometimes the typical developmental pattern does not fit.
In actual clinical practice,
Currently, there are few obstetricians and gynecologists who actively use baby nub tests to determine the gender of a baby.
The reason is, "We don't want to confuse pregnant women with uncertain information."
This is because we are concerned as medical professionals.
In my experience, even if you guess "boy" at 12-13 weeks pregnant,
A case where a definitive test at 20 weeks of pregnancy showed the baby was a girl
I've seen many of them.
Especially for first-time pregnant women,
There is often strong expectation for early gender determination,
The shock is great when the results change later.
So, does that mean baby nubs are completely pointless?
That is not the case at all.
If you think of it as "one of the joys of early pregnancy,"
I think it's well worth it.
However, please be aware of the following points:
- It's just a guess, not a confirmation
・Until a definitive diagnosis is made around the 20th week of pregnancy, the test will be used only as a reference.
・Be prepared to accept that the results may change.
With a light-hearted attitude of "If I win, I'll be lucky♪"
We want you to enjoy Baby Nab.
I think that's the healthiest way to interact.
The truth about gender determination using ultrasound
A complete guide to how boys and girls see
How to correctly view "protrusions" and "three lines"
Five points to avoid false positives
"Doctor, what is this white area on the ultrasound image?"
"Does this line mean it's a girl?"
When you receive an ultrasound image at your prenatal checkup,
Many pregnant women ask this question.
It is true that determining the gender of a baby from a black and white ultrasound image is difficult.
Without medical expertise, this is difficult.
However, knowing the correct way to look at it will enable pregnant women to make some judgments themselves .
First, let me explain the basic principles of gender determination using ultrasound.
[How ultrasound examination works]
Ultrasound (echo) is a signal that is sent back to the mother's body when sound waves are reflected by the baby's body.
It is a technology that displays images.
・Hard tissue (bones, etc.) → Appears white
・Soft tissue (muscle, etc.) → Appears gray
・Liquids (such as amniotic fluid) appear black
Because the baby's external genitalia are made of soft tissue,
The shape can be seen by the contrast with the surrounding amniotic fluid (black).
Now, let's take a closer look at the distinctive features of boys and girls.
[How boys see]
1. "Peanut-shaped" protrusions
Between the legs from around 14-15 weeks of pregnancy
You can see white shadows that look like peanuts or ovals.
This is the future penis and scrotum.
This will become more apparent as the pregnancy progresses.
2. "Turtle head" shape
At around 18-20 weeks of pregnancy,
The round part like a turtle's head (glans)
The vertically extending part (penis) becomes distinguishable.
3. Forward-facing protrusions like an "arrow"
When the baby is lying on its side, the external genitalia face forward.
You can see it sticking out like an arrow.
[How it looks for girls]
1. "Three Parallel Lines"
From around 17-18 weeks of pregnancy, the vulva
You can see three parallel white lines.
This represents the folds of the labia majora and labia minora.
This is the most important indicator for determining whether the baby is a girl.
2. Leaf-like shape
Depending on the angle, the entire vulva
They may appear oval, like leaves.
3. "Absence of protrusions"
There is no forward-facing protrusion like in boys,
It presents a flat appearance.
However, in actual clinical practice,
To accurately determine these characteristics
Extreme caution is required.
[Five points to avoid false positives]
1. Check it from multiple angles
One angle alone can be misleading.
For example, if the umbilical cord is in front of the external genitalia,
It can look like a baby bump on a boy.
Experienced obstetricians and gynecologists always observe from multiple angles,
The position of the umbilical cord will also be checked before making a diagnosis.
2. Consider your pregnancy stage
It is difficult to judge in the early stages of pregnancy (14-16 weeks) because the external genitalia are not yet fully developed.
We need to understand that there are limits to certainty.
Especially in the case of girls, they are judged by "not being able to see the characteristics of boys."
More careful observation is needed.
3. Check your baby's position
Legs closed, back turned,
If you are hiding your external genitalia with your hands,
It will be difficult to make an accurate judgment.
The ideal position is for the baby to lie on his side.
The legs are slightly open.
4. Evaluate the clarity of the image
If the mother has a high BMI or low amniotic fluid volume,
The echo image may be unclear.
In such a situation, the accuracy of gender determination will decrease.
More careful judgement is needed.
5. Observe changes over time
Not just one test, but multiple tests
Check for consistent findings.
Especially if it is determined to be a boy early on,
Because the result may change to "girl" in later tests,
Continued observation is important.
[The "pitfalls" that obstetricians and gynecologists should be most careful of]
In fact, the most common mistake in determining gender is
"The baby that was thought to be a boy was actually a girl."
This is the pattern.
Why does this happen?
The umbilical cord looks like a protrusion
- The swelling on the girl's vulva looks like a protrusion
Toes look like protrusions
- Echo artifacts (mechanical misidentification)
These "fake protrusions" are mistaken for real male genitalia.
On the other hand, there are cases where a baby thought to be a girl turns out to be a boy.
It is characterized by being relatively small.
Because the boy's protrusion
This tends to become more apparent as the pregnancy progresses.
When I tell pregnant women,
This point is fully explained,
"Especially the initial determination of the boy's birth is not definitive."
I try to make sure that you understand this.
Finally, there is something important I would like to say to pregnant women.
Gender determination by ultrasound examination
While it is a "scientific diagnosis that brings together the best of medical technology,"
It is also a "human judgment that is not 100% certain."
No matter how experienced a doctor is,
The reality is that sometimes we make mistakes.
The important thing is to accept gender determination as "one piece of reference information" and
Whatever the outcome,
I think it's about cherishing the love you have for your baby as it grows healthily inside your womb .
Gender determination using NIPT prenatal testing
The secret to 99% accuracy from the 10th week of pregnancy
The difference between certified and non-certified facilities
An obstetrician-gynecologist explains the value of 140,000 yen
"I want to know the gender of my baby as soon as possible and for sure."
The latest technology that meets the needs of mothers like this
This is NIPT (new type prenatal testing) .
From as early as 10 weeks of pregnancy,
Gender determination is possible with a high accuracy of 99%
This is why it is attracting attention.
But can you really know that quickly and for sure?
"Is it worth spending 140,000 yen?"
Many mothers must be wondering, ``Why?''
As an obstetrician-gynecologist, I will tell you the truth about NIPT.
[What is NIPT? An easy-to-understand explanation of how it works]
NIPT (Non-Invasive Prenatal Testing)
It got into my mother's blood
This is a test that examines "DNA fragments derived from the baby."
In fact, from around the 10th week of pregnancy,
The baby's DNA appears in the mother's blood.
By reading this DNA fragment using the latest genetic analysis technology,
- Presence or absence of chromosomal abnormalities
・Baby's gender
It is possible to determine the following.
"Why is such high accuracy of 99% possible?"
The reason for this lies in the way gender determination works.
For boys:
A Y chromosome is detected in the mother's (XX chromosome) blood.
→ Determined to be a boy
For girls:
No Y chromosome detected in the mother's blood
→ Determined to be a girl
Unlike an ultrasound examination, where you judge by looking at the shape,
To confirm gender at the genetic level ,
This allows for incredibly high accuracy.
[Two "faces" of NIPT that moms should know]
There are two main types of NIPT:
1. NIPT at a certified facility
・Target: Pregnant women aged 35 or over or at medical risk
・Test contents: Only three chromosomal abnormalities (Down syndrome, etc.)
・Gender determination: Generally not performed
・Cost: Approximately 200,000 yen
・Support: Comprehensive genetic counseling
2. NIPT at non-certified facilities
・Target: No age restrictions
・Test content: Whole chromosome + gender determination option
・Gender determination: Possible if desired
・Cost: Approximately 100,000-150,000 yen
・Support: Varies depending on facility
"If I just want to know the gender, which one should I choose?"
I get this question a lot,
The answer is not simple.
The first thing you need to understand is that
NIPT is not originally a "test for determining gender"
That is what it means.
The main purpose of NIPT is to
Early detection of chromosomal abnormalities in babies
The goal is to establish an appropriate medical system.
Gender determination is, so to speak, "bonus" information.
[Is it worth 140,000 yen? An obstetrician-gynecologist's honest opinion]
"140,000 yen is too expensive just to find out the gender."
That's my honest opinion.
because,
・Ultrasound tests have an accuracy rate of over 95% at 20 weeks of pregnancy
・The cost is included in the regular prenatal checkups
・The difference is only about 10 weeks.
That's why.
However, NIPT may be worth considering if:
1. Concerns about the risk of chromosomal abnormalities during advanced pregnancy
2. Family history of genetic disorders
3. Having previously conceived a baby with a chromosomal abnormality
4. Severe anxiety is interfering with your pregnancy
In such cases, "gender determination" is a secondary benefit.
It is conceivable.
Important things to know before undergoing NIPT
1. It's not 100%
Even if it's 99% accurate, there's still a 1% chance of a false positive.
In particular, accuracy may be reduced if:
・Twin pregnancy
・Mother's own chromosomal abnormalities
- When the concentration of fetal DNA is low
2. Judgment may be withheld
There is a probability of about 0.3-0.4% that the decision will be pending.
Re-examination may be necessary.
3. Psychological burden
In the unlikely event that a chromosomal abnormality is discovered,
Regarding psychological shock and future decisions,
This should be discussed with the couple in advance.
What I want to tell moms
NIPT is certainly an amazing technology.
But, just because I wanted to know the gender as soon as possible
It's not an easy choice to make.
What's important is,
Why do you want to know the gender so early?
Couples should discuss this thoroughly.
Do you want to start preparing early?
-Because you need time to think of a name?
・Is it simply for fun?
None of the reasons are wrong.
However, even with echocardiography
You will know for sure by the 20th week (6th month) of pregnancy.
There will still be plenty of time to prepare at that time.
If you are considering NIPT,
After receiving sufficient counseling from a reliable medical institution
I recommend you to decide.
Baby's health and mom's peace of mind
Because it's more important than anything.
12 Gender Superstitions Explained
Does it really predict morning sickness and belly shape?
Why is it 50% accurate even with zero medical evidence?
Experiences of 1,500 pregnant women
"I'm having terrible morning sickness, so I wonder if it's a girl?"
"Your belly is sticking out so it must be a boy!"
During pregnancy, from mothers and experienced mothers
Have you ever been told something like this?
Gender superstitions have been passed down since ancient times.
Even though I know there is no medical basis for it,
It somehow bothers me...
I understand very well how a mother feels.
As an obstetrician-gynecologist, I have experienced countless
"It was Jinx Street!"
"I didn't get it at all..."
I have heard people say this.
This time, we will be sharing the experiences of 1,500 pregnant women.
Based on medical verification,
I'll tell you the truth about gender superstitions.
[12 of the most famous gender superstitions]
1. Determined by the severity of morning sickness
"Severe morning sickness → Girl"
"Mild morning sickness → Boy"
Chance of winning: Approximately 52%
2. Determine by the shape of your belly
"jump forward → boy"
"Spread out horizontally → Girl"
Chance of winning: Approximately 48%
3. Judging by food preferences
"Sour/Salty → Boy"
"Sweets → Girls"
Chance of winning: Approximately 50%
4. Judging by the mother's facial expression
"Getting tight → Boy"
"Become gentle → Girl"
Chance of winning: Approximately 49%
5. Determined by the intensity of fetal movements
"Strong fetal movement → boy"
"Quiet fetal movements → girl"
Chance of winning: Approximately 51%
6. Determined by changes in body hair
"Body hair gets thicker → Boys"
"No change → Girl"
Chance of winning: Approximately 47%
7. Dreams
"The gender that appeared in the dream → same"
Chance of winning: Approximately 53%
8. Chinese Gender Selection Calendar
"Calculate based on mom's age and month of conception"
Chance of winning: Approximately 50%
9. Judging by the balance of power within the family
"Mom is strong → Boy"
"Daddy is strong → Girl"
Chance of winning: Approximately 48%
10. Determined by the swelling of the heel
"Right foot → Boy"
"Left foot → Girl"
Chance of winning: Approximately 49%
11. 5 Yen Coin Fortune Telling
"Back and forth movement → boy"
"Draw a circle → Girl"
Chance of winning: Approximately 50%
12. Judging by the older child's reaction
"Show interest → opposite sex"
"Indifferent → Same sex"
Chance of winning: Approximately 52%
"Aren't you surprised by the results?"
Every jinx,
The probability of winning is about 50%
That is, the probability is the same as flipping a coin.
[Why are jinxes 50% accurate?]
There is a good reason for this phenomenon.
1. Probability Problems
The probability of the baby's gender being male or female is 1:1.
Either way, you'll get 50% right.
2. Selectivity of memory
The impressive experience of "I won!" is easy to remember,
It's easy to forget the "wrong" experiences.
3. Confirmation bias
Focus on information that matches your expectations
This leads to a psychological tendency to disregard information that does not fit the description.
[When medically examined...]
So, what about these jinxes?
Is there a medical basis for this?
About the severity of morning sickness
In fact, if you are pregnant with a girl,
Research has shown that morning sickness tends to be more severe.
The reason is the amount of female hormone (estrogen) secreted .
For girls, from both mom and baby
Female hormones may overlap, causing severe morning sickness.
However, there is a great deal of individual variation,
It's not "absolute."
About "belly protrusion"
This is entirely determined by the shape of the mother's pelvis and body type .
・Narrow pelvis → protruding forward
・Wide pelvis → Spreads out to the sides
・First birth → The belly tends to protrude forward
・Multiparous women → The stomach tends to spread out to the sides
It has nothing to do with the gender of the baby.
Regarding food preferences
Changes in food preferences during pregnancy
This is due to changes in hormone balance .
Not the baby's gender
Mom's constitution and previous dietary habits,
It is affected by stress situations etc.
[Real experiences of moms]
Ms. A (32 years old, gave birth to a boy)
"I didn't have any morning sickness and people around me kept saying, 'It's a boy.
My stomach was sticking out and I just wanted to eat sour things...
It turned out to be a boy, so everyone was surprised!
But maybe it was just a coincidence."
Ms. B (28 years old, gave birth to a girl)
"With my first child, I had mild morning sickness and it was a boy.
I thought this time I would have a second child, but I had severe morning sickness and ended up with a girl.
I thought it was a jinx!
My third child was a boy, even though I had severe morning sickness.
In the end, it's unreliable (laughs)."
Ms. C (35 years old, gave birth to twins)
“Being twins, the whole jinx thing was confusing.
I have severe morning sickness and my stomach is sticking out both to the sides and forward...
The result was twins, a boy and a girl.
I realized that jinxes are unreliable after all."
[How to deal with jinxes]
So, does that mean gender jinxes are completely meaningless?
I don't think so.
The true value of the jinx is
It provides "fun during pregnancy."
・Enjoy predictions with the whole family
- A conversation starter during pregnancy
Deepen your love for your baby
It relieves anxiety
These are very important effects.
However, please note the following:
Understand that it's not an absolute rule
Don't expect too much
・Don't be discouraged even if you miss
・Enjoy it as entertainment
And most importantly,
Whatever the outcome of the jinx,
It's the feeling of loving the baby in your belly .
Whether it's a boy or a girl,
With lots of love from mom and dad
The baby that is born
I'm sure he will grow up to be a happy child.
Gender jinxes are
Coloring such happy times
It's one of the little pleasures.
Why does misidentification of sex occur?
An obstetrician-gynecologist explains the probability and countermeasures
The number of weeks of pregnancy, the position of the baby, and the umbilical cord affect
The three major causes and how to avoid them
"At my 20-week checkup, I was told it was a boy,
The baby was a girl..."
Hearing these experiences,
I'm sure many mothers are feeling anxious.
Misjudgments in sex determination are not uncommon.
During my 15 years of experience as an obstetrician-gynecologist,
I myself have made the wrong decision a few times.
Every time this happened, I felt so sorry for the pregnant women.
But the important thing is,
Understand why misjudgments occur
It's about having the right mindset .
This time, we will look at the mechanism of false positives and
I will be honest about the measures we will take.
[Probability of false positives: realistic numbers]
First, how often do false positives occur?
Actual data broken down by week is shown below.
14-15 weeks of pregnancy: false positive rate approximately 15-20%
16-17 weeks of pregnancy: false positive rate approximately 10-15%
18-19 weeks of pregnancy: false positive rate approximately 5-10%
After 20 weeks of pregnancy: False positive rate: 2-5%
This means that even after 20 weeks of pregnancy,
2-5 out of 100 people may be misdiagnosed
That is the reality.
Look at these numbers,
Don't you think that's surprisingly many?
Echocardiography is certainly an amazing technology, but
As long as "humans look at images and make judgments,"
100% accuracy is impossible .
[Three major causes of false positives and specific examples]
1. Pregnancy is too early
This is the most common cause of false positives.
[Case 1: "Boy" at 14 weeks → Actually a girl]
At around 14 weeks of pregnancy, even girls may temporarily
You may see protruding structures.
This is called the "genital tubercle"
This is the part that forms the external genitalia common to both men and women.
In girls, the subsequent development
The protrusions will become less noticeable,
In the early stages, it is easy to mistake it for a boy's external genitalia.
Actual experience:
"At 14 weeks, my husband and I were delighted to hear that it was a boy.
But at my 18-week checkup, I was told, "It might be a girl."
In the end it was a girl, but I used the boy's items I had prepared.
I was at a loss as to what to do." (Mr. D, 29 years old)
2. Baby's position and direction
Because babies are constantly moving,
It is not always possible to position the external genitalia in a way that makes it easy to see them.
[Case 2: The umbilical cord gets in the way]
If the umbilical cord is in front of the external genitalia,
It can look like a boy's bump.
Also, if you are covering your external genitalia with your hands or feet,
It becomes difficult to judge.
Actual experience:
"At every checkup, I was told, 'You're hiding again today.'
I have a friend who didn't find out the gender of her baby until after birth.
The baby was a healthy baby boy." (Ms. E, 31 years old)
3. Performance of the echocardiogram equipment and the experience of the technician
The higher the resolution of the echo device,
This provides clearer images and allows for more accurate judgment.
In addition, the experience of the doctors and technicians who perform the tests is also important.
This has a significant impact on the accuracy of the judgment.
[Case 3: Difficulty in judgment due to image quality]
If the mother has a high BMI
In case of oligohydramnios,
The echo image may be unclear.
In this situation,
Even experienced doctors can be confused in their diagnosis.
[Tendency to misjudge: Why there are so many male-to-female matches]
Interestingly, there are clear trends in false positives.
"Predicted as a boy → Actually a girl": Approximately 70%
"I guessed it was a girl, but it was actually a boy": About 30%
Why is there such a bias?
Reason 1: Fake protrusions
Swelling of the umbilical cord, toes, or vulva
May look like male genitalia
Reason 2: What girls are uniquely "not"
The determination of whether a boy is a girl is based on the absence of any protrusions.
It is difficult to distinguish from cases where the sting is merely hidden.
Reason 3: Psychological bias among doctors
"I can see something that looks like a protrusion,"
The psychology of wanting to assume it's a boy is at work
[Five measures to avoid false positives]
It cannot be completely avoided, but
You can reduce the risk of false positives by:
1. Asking for Multiple Confirmations
"Today, there is a high possibility that ____ will occur,
Please check it at your next checkup."
Ask your doctor.
It is not determined by one decision,
Obtaining consistent results multiple times is important.
2. Ask for the basis for the decision
"Which part did you look at to make your decision?"
"How certain are you?"
Let's ask ourselves this question.
If your doctor can clearly explain
It is considered to be more reliable.
3. Wait until after the 20th week of pregnancy
If you don't need to know in a hurry,
It is most reliable to wait until after 20 weeks of pregnancy to get the results.
At this stage, the external genitalia are fully developed,
The risk of false positives is significantly reduced.
4. See it as a possibility, not a certainty
No matter how confident your judgment is,
Understand that it's not 100% certain.
"Based on current findings, there is a high possibility that ____"
It is important to take this information as it is.
5. Get a second opinion
Before making any particularly important decisions (such as deciding on a name),
It is also helpful to get the opinion of another doctor.
[How to prepare in case of a false positive]
Even if it was a misjudgment,
Remember the following:
1. You're not bad
Misdiagnosis is a limitation of medical technology,
It's not that you did anything wrong.
2. Your baby's health comes first
Whatever your gender,
The most important thing is that the baby is born healthy.
3. Preparation will work
Nowadays, it can be used regardless of gender.
There are lots of baby products.
It is entirely possible to purchase additional items after the baby is born.
4. New enjoyment is born
Even if the gender is different from what you expected,
This brings new discoveries and joys.
Finally, as an obstetrician-gynecologist
I have something to say to all the moms out there.
Gender determination is for "reference only"
It is not "absolute truth."
What's important is what's in your stomach
It is the love for our children to grow up healthy.
Whether it's a boy or a girl,
The miracle of being born into this world
Let's keep a close eye on it.
Complete guide to determining the gender of a baby boy
The reason you can tell from 14 weeks and how to avoid mistakes
The true identity of "peanut-shaped" and "turtle-head"
Key points to determine if your baby is a boy
"This white part on the ultrasound image is a symbol of a boy, right?"
This is one of the most common questions asked during prenatal checkups.
Gender determination for boys is possible at an earlier age than for girls ,
At the same time, it is also prone to misreading.
As an obstetrician-gynecologist, I have
Cases where "I thought it was a boy but it turned out to be a girl"
I have experienced it.
This time, we will explain how to accurately determine whether the baby is a boy or a girl.
We will explain in detail the points to avoid mistakes.
[Medical reasons why you can tell early whether you're having a boy]
Why can boys be diagnosed earlier?
The answer lies in the action of the male hormone testosterone .
8 weeks pregnant:
The Y chromosome signals the start of male hormone secretion
Pregnancy 10-12 weeks:
Genital tubercle begins to grow forward
The prototype of the future penis is formed
Pregnancy 14-15 weeks:
External genitalia protrusions are clearly visible
Observed as "peanut-shaped" on ultrasound
Pregnancy 18-20 weeks:
Clear distinction between penis and scrotum
The "turtle head" shape can be seen
This positive growth process has
Boys can be diagnosed 3-4 weeks earlier than girls .
[Characteristics of determining whether a boy is a boy by week]
14-15 weeks of pregnancy: early assessment period
Visible features:
- Small protrusion between the legs
- Shapes like peanuts or ovals
- An angle of more than 30 degrees to the spine
Points to note:
・It may still be small and difficult to judge
・Be careful not to mistake it for the umbilical cord
・The confidence level is about 70-80%
Actual experience:
"At my 14 week checkup I was told it was probably a boy.
The doctor also said, "It's still too young to be sure."
They gave me some advance warning so I didn't get my hopes up too high."
(Ms. F, 30 years old, gave birth to a boy)
16-17 weeks pregnant: rising confidence
Visible features:
- Protrusions are more clearly visible
- Scrotal swelling can be confirmed
・The overall shape is "male genitalia-like."
Points to note:
・May not be visible depending on posture
・Even if you are hiding it with your hands and feet
・The confidence level is about 85-90%
After 18 weeks of pregnancy: Definitive evaluation period
Visible features:
-Penis and scrotum clearly distinguishable
・Round parts like a turtle's head
・The penis part that extends vertically
-Bulges on the left and right sides of the scrotum
Points to note:
Almost certain, but not 100%
・Confidence is over 95%
[Common "misidentification" patterns when determining whether a boy is a boy]
1. Confusion with the umbilical cord
This is the most common mistake pattern .
When the umbilical cord passes in front of the external genitalia,
It may look like a male genital protrusion.
How to tell:
・Umbilical cord: Wavy and moving
・Male organ: Moves in unison with the baby
Check from multiple angles
2. Confusing with toes
When your baby crosses his legs,
The toes may appear as bumps.
How to tell:
・Toes: Five toes appear together
- Male genitalia: Appears as a single protrusion
・Check whether it is linked to the movement of the feet.
3. Confusion with vulvar swelling in girls
During the second trimester, the girl's vulva
There may be temporary swelling.
This can sometimes look like a male organ,
Careful observation is required.
How to tell:
Swelling: Round, bulging shape
・Male genitalia: Protruding forward
As the weeks go by, the swelling will go down
[Five checkpoints to determine if you're having a boy]
1. Check the "three structures"
A boy's external genitalia consists of three structures:
-Penis (rounded tip)
- Penile body (the part that extends vertically)
- Scrotum (bulges on both sides)
If all three of these are confirmed,
It's very likely to be a boy.
2. Check the angle and direction
The external genitalia of boys are
At an angle of more than 30 degrees to the spine
It protrudes towards the front.
If it is horizontal or facing downwards,
You need to consider the possibility of a girl.
3. Multiple, consistent checks
Not just a one-time test,
Are findings consistent across multiple checkups?
It's important to check.
4. Consider your baby's position
Ideal viewing conditions:
・Baby is lying on his side
・Legs slightly apart
- Not covering with hands
The umbilical cord is not in the way
5. Judgment based on the number of weeks of pregnancy
14-15 weeks pregnant: consider it a possibility
16-17 weeks pregnant: Highly accurate
After 18 weeks of pregnancy: Almost certain
[Criteria actually used by obstetricians and gynecologists]
When we obstetricians determine that the baby is a boy
Here are the actual standards:
[Certainty Level A (95% or higher confidence)]
・After 18 weeks of pregnancy
・All three structures are clear
-Confirmed from multiple angles
・Umbilical cord position confirmed
[High Probability Level B (85-90% confidence)]
・Pregnancy 16-17 weeks
- Protrusions and scrotum can be seen
-Clear forward protrusion
-Can be distinguished from other structures
[Probability level C (70-80% confidence)]
・14-15 weeks of pregnancy
-Protrusion-like structure
・Angle and direction are phallic
- However, it is small and unclear
[Difficulty level D (confidence level 50% or less)]
・Before 13th week of pregnancy
・Poor posture
・Image is unclear
・Difficult to distinguish from other structures
[Experiences of moms of boys]
Ms. G (27 years old, first child):
"I was so happy when they told me it was a boy at 16 weeks.
But the teacher said, "It's not certain yet, so let's check again next time."
He said that to me, so I was half excited and half anxious.
At the 20-week checkup, I was told again that it was definitely a boy.
I was finally able to start preparing with peace of mind."
Ms. H (33 years old, second child):
"My first child was a girl, so I thought it would be nice to have a boy this time.
When I was told at 15 weeks that I was having a boy,
Because I had experienced it with my first child, I thought, "I don't know yet."
I tried not to expect too much.
In the end, it turned out to be a boy, but I'm glad I was able to respond calmly."
[Advice for moms who have been diagnosed with a boy]
1. Understand the difference in confidence levels depending on the number of weeks
The 14-15 week pregnancy diagnosis is taken as a "possibility"
It is wise to wait to check after 18 weeks.
2. Prepare in stages
Rather than buying a lot of boy's products due to early judgment,
Keep it to a minimum until you are more confident.
3. Prepare your name carefully
Not just a boy's name
It's a good idea to consider girls' names as options as well.
4. When to tell your family
Reports at low confidence levels are
This may cause confusion later.
Don't forget to preface your statement with "I'm not sure yet."
Finally, as an obstetrician-gynecologist
Here are some important things to know about determining if your baby is a boy.
It is certainly possible to determine whether a baby is a boy or a girl early on,
"Fast" does not mean "reliable."
No matter how clear it may seem,
There are always exceptions in medicine.
I hope you understand.
The important thing is not to get excited or upset about the results,
It's the feeling of love for the baby growing healthily inside the womb .
Whether it's a boy or a girl,
Lots of love from mom and dad
The baby that is born
He'll be the happiest kid in the world.
Complete guide to determining a girl's gender
Why you should wait until 17 weeks and how to tell for sure
"Three lines" and "leaf shape" identification techniques
Girl-specific points
"Is it harder to judge girls than boys?"
This is a question that is often asked during prenatal checkups.
Certainly, determining the gender of girls is easier than determining the gender of boys.
Careful and detailed observation is required .
Because the girl's judgement is
"Lack of boyish characteristics" + "Having a structure unique to girls"
Because you need to check both.
As an obstetrician-gynecologist, I have
"I thought it was a girl but it was a boy"
"They said it was a boy but it was a girl"
I have experienced a case like this.
This time, we will introduce the accurate method of determining whether you are a girl or not.
I'll tell you how to tell the difference for sure.
Why do girls have to wait until 17 weeks?
While boys can be diagnosed at 14-15 weeks,
Why girls need to wait until 17-18 weeks
I will explain it medically.
[Less influence of female hormones]
For boys, from around 8 weeks of pregnancy
Influenced by male hormones (testosterone)
The external genitalia actively grow.
On the other hand, for girls
Because there is no specific hormonal stimulation,
It's a natural, slow process of development .
[The difficulty of confirming something does not exist]
To judge girls
"There are no male genital-like protrusions"
It is essential to check this.
But proving that there isn't
It's harder to prove something exists.
・It may just be hidden by the baby's position.
・It may just be that it's too small to be seen.
・It may just be hidden by the umbilical cord
To eliminate these possibilities,
A more careful observation period is needed.
[Characteristics and changes in determining whether a girl is a girl by week]
14-16 weeks of pregnancy: difficult period to determine
Visible features:
External genitalia are still underdeveloped
Difficulty distinguishing between men and women
・It is possible to confirm that there are no protrusions
Points to note:
There's a possibility that a boy is hiding
・The confidence level is about 60-70%
・"Maybe it's a girl" level
Actual experience:
"At 15 weeks, I was told, 'I don't see any bumps right now, but
"It's not certain yet," he said.
The teacher was very cautious, so I tried not to get my hopes up too much."
(Ms. I, 32 years old, gave birth to a girl)
17-18 weeks pregnant: rising confidence
Visible features:
・The structure of the vulva is clearly visible
・"Three parallel lines" can be seen
-Ability to distinguish between labia majora and labia minora
Points to note:
・It may be difficult to see depending on the angle
・The confidence level is about 85-90%
・"High probability of being a girl" level
After 19 weeks of pregnancy: Definitive evaluation period
Visible features:
-Clear labia majora, labia minora, and clitoris
- Overall shape like a leaf
Complete absence of phallic projections
Points to note:
Almost certain, but not 100%
・Confidence is over 95%
[Three important points to observe when determining if your baby is a girl]
1. Check for "three parallel lines"
This is the most important indicator for determining whether it's a girl or not.
The identity of the three lines:
・Two outer folds: folds of the labia majora
・The one in the middle: the fold of the labia minora
Points to check:
・Lined up in parallel
・Symmetrical
- The length is almost the same
Points to note:
・Difficult to see depending on the angle
May be unclear due to temporary swelling
・May be hidden by the shadow of the umbilical cord
2. Check the overall shape
The female vulva as a whole
Shapes like "leaves" or "hearts"
It is characterized by its appearance.
Shape features:
- Oval and flat
No forward protrusion
・Symmetrical
-Slightly narrow at the top and wide at the bottom
3. Confirm the absence of phallic structures
This is the most important thing when determining whether a girl is a girl,
This is the hardest part.
Things to check:
No protrusions in front
No penis-like structure
No scrotal swelling
・There are no elements that make you feel "boyish"
[Common "misidentification" patterns when determining whether a girl is a girl]
1. Temporary vulvar swelling
During the second trimester, the girl's vulva
There may be temporary swelling.
This looks like the male scrotum,
They may be mistakenly identified as "boys."
How to tell:
Swelling: The whole area swells up in a round shape
・Scrotum: A bulge separated into left and right
Swelling will improve over time
Actual experience:
"At 17 weeks, I was told, 'It might be a boy,'
At 20 weeks, it changed to "It's a girl after all."
When I asked the doctor, he said it was just temporary swelling."
(J, 29 years old, gave birth to a girl)
2. Confusion with the umbilical cord
If the umbilical cord is close to the vulva,
It may look like male genitalia.
How to tell:
・Umbilical cord: undulating
・Vulva: One with the baby
- Check from multiple angles
3. Confusing with feet and hands
When your baby is in a certain position,
The toes or hands may look like external genitalia.
[Five checkpoints to determine if the baby is a girl]
1. Multiple, consistent observations
Determining whether you're having a girl isn't just a one-time test.
Consistent findings across multiple checkups are important.
Ideal review schedule:
・17th week: First evaluation
・19 weeks: Confirmation
・22 weeks: Final check
2. Determine optimal observation conditions
Ideal conditions:
- Baby is lying on his back or side
・Legs slightly apart
The umbilical cord is not in the way
- Adequate amount of amniotic fluid
3. Check the details of the "three lines"
It's not just that you can see the lines,
Let's take a closer look at its features.
Detailed check items:
- Number of lines (must be 3)
・Parallelism (neatly lined up)
・Symmetry (balance between left and right)
- Length (almost the same length)
4. Focus on the overall impression
Not just the details,
The "femininity" of the entire vulva
We will make a comprehensive judgment.
5. Confirm the complete absence of male genitalia
From any angle,
In any position,
The fact that the male genitalia structure cannot be seen
I will confirm.
[Criteria for determining whether a girl is a girl, as actually used by obstetricians]
[Certainty Level A (95% or higher confidence)]
・After 19 weeks of pregnancy
・Three lines are clearly visible
- Leaf-like overall shape
Complete absence of male genital structures
Multiple consistent observations
[High Probability Level B (85-90% confidence)]
・17-18 weeks of pregnancy
・Three lines can be seen
- Absence of protrusions
・Female genitalia-like shape
[Probability level C (70-80% confidence)]
・15-16 weeks of pregnancy
No protrusions are visible
・Feminine impression
However, the structure is unclear
[Difficulty level D (confidence level 50% or less)]
・Before 14th week of pregnancy
・Poor posture
・Image is unclear
・Insufficient decision material
[Experiences of moms of girls]
Case of Mr. K (31 years old, first child):
"At 17 weeks, we were told it was most likely a girl.
After being told that three lines are visible,
When I saw the ultrasound picture, I was so impressed, I thought, "It's true!"
Once we were confirmed at 20 weeks, we started seriously thinking about names for our baby girl."
Mr. L (34 years old, second child):
"My first child was a boy, so I wanted a girl this time.
When I was told at 16 weeks that it might be a girl
I was happy, but the doctor said, "It's not certain yet."
So I was careful not to get my hopes up too much.
In the end, it was a girl, and the girl's items I had prepared were
I'm glad it didn't go to waste."
[Advice for moms who have been diagnosed with a girl]
1. They prepare more carefully than boys.
Because the determination of girls is slower than that of boys,
Avoid buying in bulk early.
2. Deepen your understanding of the "three lines"
When you get the ultrasound picture,
Ask your doctor to show you where the "three lines" are.
The more you understand, the more at ease you will feel.
3. Understand the difference in reliability depending on the number of weeks
There is a big difference in confidence between 17 and 20 weeks.
It is safe to make important decisions after 20 weeks.
4. Think about a boy's name
In case of a misjudgment,
It's a good idea to think of some boy's names as well.
Finally, regarding gender determination for girls
I have something important to tell you.
When judging a girl, "discretion" is the most important thing.
They don't have the "clear vision" of boys,
It requires careful observation and comprehensive judgment .
Therefore, it takes time to make a decision,
That makes the joy when it's confirmed all the greater.
Whether it's a boy or a girl,
Being nurtured in mother's womb
An irreplaceable life.
While enjoying the gender determination,
The most important thing is to continue to wish for healthy growth.
It's the most important thing.
Wanting to know the gender quickly vs. wanting to look forward to it
Advantages and disadvantages of each
Names, preparations, and mindsets change
The choices moms make as seen by obstetricians
"I want to wait until the baby is born to find out the gender."
"I want to know as soon as possible so I can be prepared."
During prenatal checkups, mothers are divided into these two camps.
There is no right or wrong answer,
Each has different advantages and disadvantages .
15 years as an obstetrician-gynecologist
From my experience working with over 3,000 mothers,
We'll discuss both options in detail.
[Moms who want to know sooner: About 75%]
In fact, about 75% of modern pregnant women
"I would like to know the gender as soon as possible."
Let's take a closer look at why.
[Benefits of early gender determination]
1. You can think carefully about the name
This is the most common reason.
Once you know the gender, narrow down the candidates.
You can take your time thinking about the name.
Actual experience:
"We found out it was a boy at 16 weeks and started thinking about names from there.
Check the number of strokes, sound, and meaning.
The whole family discussed and decided together.
I'm glad I was able to call him "○○-kun" as soon as he was born."
(Ms. M, 28 years old, gave birth to a boy)
2. Easily prepare baby supplies
If the gender is known,
Clothes, toys, room decorations, etc.
Specific preparations can now be made.
・For boys: blue, green, vehicle patterns, etc.
・For girls: pink, floral, animal prints, etc.
Economic benefits:
・You can purchase items during sales and bargains.
- Plan your shopping to avoid waste
・It's easy to get hand-me-downs
3. Be prepared
By knowing the gender,
You can visualize your baby more clearly.
How to prepare to become a "boy mom":
・Determination to raise active and energetic children
- Imagine enjoying sports and adventures together
・Think about your future relationship with your "son"
How to prepare to be a "girl mom":
・Determination to protect a sensitive and gentle child
・Imagine enjoying fashion and beauty together
・Think about your future relationship with your "daughter"
4. It strengthens family bonds
By knowing the gender,
This will allow the whole family to have a concrete discussion.
Conversation with a partner:
・Call them by their name, such as "○○-kun (○○-chan)."
・Talk about dreams and hopes for the future
・The fun of choosing baby products together
If you have older children:
・Imagine the relationship between siblings in concrete terms
・Older children feel like they are big brothers and sisters
・You can see the final form of your family structure
[Disadvantages of early gender determination]
1. Risk of false positives
This is the biggest disadvantage.
To determine if you are 14-18 weeks pregnant,
There is still a 15-5% chance of false positives.
Actual experience:
"At 16 weeks, I was told it was a boy and started wearing boys' clothes.
I ended up buying a lot.
When I was told at 20 weeks that it was a girl,
I was happy, but at the same time, I was troubled."
(Ms. N, 30 years old, gave birth to a girl)
2. Fixed expectations
If you find out the gender early on,
Sometimes expectations of that gender can become too strong.
・Expectations for boys: "I want him to grow up strong and strong"
・Expectations for girls: "I want her to grow up to be cute"
Such stereotypes,
This can affect the upbringing of the child from birth onwards.
3. Pressure to prepare
Once you know the gender,
The pressure to "prepare properly"
I sometimes feel this way.
・Increased economic burden
- Obsession with perfect preparation
Expectations and advice from those around you
[Moms who want to look forward to it: approx. 25%]
On the other hand, about 25% of mothers
"I want to look forward to the birth" is selected.
Benefits of being fun
1. The excitement of childbirth is doubled
This is the biggest advantage .
Overcoming long labor pains,
The moment the baby is born
"It's a boy!" "It's a girl!"
It's an exceptionally moving experience to hear this.
Actual experience:
"When the contractions were so painful I thought, 'I can't do this anymore,'
The desire to know the gender of the baby
He gave me the final strength.
The moment I heard, 'It's a girl!' I couldn't stop crying."
(Ms. O, 32 years old, gave birth to a girl)
2. It helps avoid gender bias
By not knowing the gender,
The baby as a person
You can love purely.
・"Because it's a boy, ○○"
・"Because I'm a girl, I do ____"
Not bound by the fixed idea that
You can respect your baby's individuality.
3. The fun continues during pregnancy
By not knowing the gender,
You can enjoy the imagination throughout your pregnancy.
-The baby is moving a lot today, so maybe it's a boy?
・I have severe morning sickness so I wonder if it's a girl?
・Let's guess from the shape of the stomach
This kind of "guessing game"
It's a great joy during pregnancy.
4. Simplicity of preparation
By not knowing the gender,
It makes preparation simple.
-Gender-neutral yellow or white clothing
・Baby products with simple designs
・Put off anything that isn't really necessary
As a result, you can prepare without waste.
Disadvantages of the Fun Group
1. Preparation Limitations
Because the gender is unknown,
There is a limit to what can be prepared.
・Clothing: Limited to white, yellow, green, etc.
・Name: It is necessary to consider both male and female names.
・Room: Gender-neutral design
2. Peer pressure
"Why don't you ask about the gender?"
"I wish I'd known sooner."
You may feel stressed by the voices around you saying things like this.
3. The rush of postpartum life
To prepare for gender specific conditions from birth,
Post-natal life can be hectic.
・Final decision on the name
-Purchasing gender-appropriate clothing
・Room rearrangement
[Both options from an obstetrician's perspective]
With 15 years of experience,
I feel that both options are worthwhile.
[Suitable for moms who like to learn early]
・The type who wants to proceed with things in a planned manner
・The type who wants to be well prepared and feel at ease
・The type who likes to talk about specific details with their family
・First-time mothers with high anxiety
[Moms who enjoy themselves]
・A type that values surprises and emotions
- People who like a simple life
- People with a rich imagination who enjoy fantasizing
・A generous type for multiparous women
What I want to tell moms
Whichever you choose,
There is no "correct answer."
What's important is,
Mom and partner talk
It's about making a choice you can be happy with .
[Advice when you're unsure about which choice to make]
1. Talk to your partner
Don't make decisions alone, always with your partner
Please consult me.
2. Don't be swayed by the opinions of others
The opinion that "Normally it's ____"
Please use this as a reference only.
3. You can change it later
Even if you think, "I want to look forward to it,"
On the way, I thought, "I want to know after all."
Things may change.
4. Either way, the love remains the same
Whether you know the gender or not,
The love for your baby remains the same.
Finally, from moms who made both choices:
Here are some commonly heard phrases.
"Whichever you choose,
The moment the baby was born was amazing."
Whether you find out the gender early or are looking forward to it,
Babies are born surrounded by their mother's love
He is the happiest child in the world.
Make your own choice,
Have a wonderful pregnancy.
Gynecologist reveals behind the scenes of gender determination
Why do some hospitals teach and others don't?
Doctors' true feelings and judgment criteria
The basis for the "confidence level of ○%" is revealed
"Why, they tell me at that hospital,
Doesn't this hospital tell you?"
This is a question I get asked every now and then during prenatal visits.
Actually, about gender determination
The reality is that policies vary greatly between medical institutions and doctors .
This time, based on my 15 years of experience as an obstetrician-gynecologist,
I don't usually talk
We will honestly tell you about what goes on "behind the scenes" of gender determination .
[Three reasons why policies vary by hospital]
1. Differences in medical institution philosophies and policies
Hospitals that actively teach:
"Our mission is to respond to the desires of pregnant women to know."
There are medical institutions that believe this way.
Features:
・Judgment begins around the 14th week of pregnancy
・Communicate it as a "possibility" early on
- Paying attention to patient requests
・Explanation by adding arrows to the ultrasound image
Hospitals that make careful decisions:
"We don't want to confuse people with uncertain information."
There are medical institutions that believe this way.
Features:
- Don't tell your partner until after the 20th week of pregnancy
・No judgment will be made unless the confidence level is 95% or higher
・Focus on medical necessity
-Treat it as reference information only
Hospitals that don't tell you anything:
"Gender is not medically necessary information"
Some medical institutions have this policy.
Features:
- Gender determination is not considered a medical procedure
・Checking your health is the top priority
・Eliminate entertainment elements
・When asked, I answered "It's fun"
2. The doctor's personal experience and personality
Even at the same hospital, different doctors
Attitudes towards gender determination may differ.
Cautious doctors:
"Doctors who have had trouble with incorrect diagnosis in the past"
Many doctors, including myself,
We have experienced confusion among pregnant women due to incorrect diagnosis.
Actual experience:
"A patient who was diagnosed with a boy at 15 weeks
When I changed into a "girl" at 20 weeks,
"I was only thinking of boy's names..."
I was disappointed.
Since then, I try not to tell people until after 18 weeks."
Proactive doctors:
"Doctors who want to see the happy faces of pregnant women"
Seeing the smile on the pregnant woman's face when she found out the gender,
Some doctors feel the "joy of being a doctor."
Actual experience:
"The moment we found out the baby's gender on the ultrasound,
When I see a pregnant woman and her husband holding hands and looking so happy,
I will be happy too.
Even in times of uncertainty, we want to provide happiness in those moments.”
3. Legal and ethical considerations
In fact, gender determination
There are also delicate aspects.
Concerns about gender selection:
In some countries, sex selection is
It has become a social problem.
Even in Japan, "It's a problem if it's not a boy (girl)"
For those who have such extreme thoughts
Consideration may be required.
Preventing misuse of abortion:
Overseas, there are cases where people are forced to leave their jobs because of their gender.
There are areas where abortion is an issue.
Among Japanese doctors,
Because of such concerns
Some teachers are reluctant to determine gender.
[Our true feelings as doctors: Criteria for determining confidence]
So, what criteria do we actually use?
Are you judging it to be "○% certain"?
I'll tell you.
[Factors that determine confidence]
1. Gestational age (30% weighting)
14th week of pregnancy: Basic score 50 points
16 weeks pregnant: Basic score 70 points
18 weeks pregnant: Basic score 85 points
20 weeks pregnant: Basic score 95 points
2. Image clarity (25% weighting)
Very clear: +10 points
Clearness: ±0 points
Somewhat unclear: -5 points
Blurred: -15 points
3. Baby position (20% weight)
Optimal posture: +5 points
Fair posture: ±0 points
Somewhat difficult to see: -3 points
Invisible: Unable to judge
4. Clarity of Features (25% weight)
Very clear: +10 points
Clear: +5 points
Somewhat unclear: ±0 points
Unclear: -10 points
Actual calculation example:
[Case 1: 16 weeks pregnant, boy confirmed]
・Number of weeks pregnant: 70 points
Image clarity: +5 points (slightly clear)
Baby's position: +3 points (fair)
Clarity of features: +8 points (clear)
Total: 86 points → 85% confidence
[Case 2: 20 weeks pregnant, girl confirmed]
・Number of weeks pregnant: 95 points
Image clarity: +10 points (very clear)
Baby position: +5 points (optimal)
Clarity of features: +10 points (3 clear lines)
Total: 120 points → 98% confidence
[Psychological aspects of the moment when doctors hesitate to make a decision]
"Should I tell him today or not?"
We are human beings too,
There are moments when it's hard to decide.
[Confusion pattern 1: 80% confidence boundary line]
80% confidence means
It's a very fine line for doctors to walk.
Reasons for reporting:
Pregnant women are really looking forward to it
・Preface your statement with "possibility"
・It is expected to be more reliable next time.
Reasons for not telling:
・I'm worried about the 20% risk of false positives
・There is a possibility that pregnant women will start preparing
I want to wait and see a little longer.
[Confusion Pattern 2: The pregnant woman's personality and situation]
With the same confidence,
The decision may vary depending on the pregnant woman.
Pregnant women who are easy to communicate with:
・They understand that "it's not certain yet"
・Calm and composed
・Experienced multiparous women
Pregnant women to be cautious:
・They are very anxious and tend to seek reliable information
・Strongly insist that you "absolutely want to know"
・I have had trouble with false positives in the past.
[The true meaning of the "doctor's words" used in gender determination]
The words we use are
Each has a clear meaning.
"It's a boy (girl)."
→ 95% or more confidence
Almost certain. The same result is likely to occur next time.
"I think it's a boy (girl)"
→ 85-90% confidence
Pretty sure, but not confirmed yet
"There's a high chance it's a boy (girl)."
→ 75-85% confidence
It seems that way, but that could change
"It could be a boy (girl)"
→ 60-75% confidence
I think so, but I'm not sure
"I still don't know today."
→ Confidence less than 50%
Impossible to judge or want to avoid judgment
Why do doctors use different words?
Looking at the same image,
Doctors may express it differently.
Cautious doctors:
Even with a 90% confidence level, it is still described as "highly likely."
Proactive doctors:
Even if you are 80% certain, you should still say "I think"
This depends on the doctor's personality and experience.
[The reactions of pregnant women that doctors find most troubling]
To be honest,
I'm troubled by the following reactions:
1. The question, "Are you absolutely certain?"
There are no absolutes in medicine.
When asked this question,
This makes me even more cautious.
2. Starting preparations with early judgment
Although I said "possibility,"
If it is accepted as confirmed information
I'm in trouble.
3. Comparison with other hospitals
"They told me at XX Hospital."
The comparison is,
It confuses doctors.
[Reactions of pregnant women that make doctors happy]
On the other hand, the following reaction
It makes me very happy as a doctor.
1. They understand uncertainty
"We know it's not a sure thing yet."
If you show that understanding,
You can safely provide information.
2. They express their gratitude
"Thank you for letting me know."
When I hear the words,
I'll have to look at it more carefully next time.
3. They accept things calmly
Don't expect too much, just take it as information
For pregnant women who receive it,
You can be more honest.
[What I would like to ask of pregnant women as a doctor]
Finally, as an obstetrician-gynecologist
I have a request for pregnant women.
1. Understand your doctor's policy
Doctors who won't tell you,
This decision was made with pregnant women in mind.
It's not "cold."
2. Embrace uncertainty
Gender determination is not 100%.
If you understand this reality,
You can communicate better.
3. Remember that your health comes first
Gender determination is "bonus" information.
Checking the baby's health
The most important goal
Don't forget.
Whether you know the gender or not,
A healthy baby growing inside the womb
My feelings of love for you remain unchanged.
While doctors and pregnant women build a relationship of trust,
I hope you have a wonderful pregnancy.
Gender determination Q&A
15 Real Concerns of Pregnant Women
"The judgement has changed" "My opinion differs from my partner's"
Actual consultation cases answered by obstetricians and gynecologists
"Teacher, this is a bit difficult to ask..."
At the end of the prenatal checkup,
There are pregnant women who ask questions shyly.
Regarding gender determination,
Many mothers have
There are "difficult worries" and "concerns" that are difficult to talk about .
This time, I will introduce the actual treatments I received over the past 15 years.
Among the questions, we answered the 15 most common concerns.
As an obstetrician-gynecologist, I will answer honestly.
[Questions regarding timing of gender determination]
Q1: Can I refuse gender determination?
A: Of course it is possible.
"I want to look forward to it until it's born."
There is absolutely no problem with that wish.
Rather, if you could let us know in advance,
The doctor will also be able to explain things to you carefully.
please:
・At the first consultation, tell the doctor that you don't want to know the gender.
・Have it recorded in the medical record
-Confirm that your partner has the same intentions
Q2: I once said I didn't want to know, but now I want to know.
A: It's natural for your feelings to change.
Your mood changes during pregnancy.
Don't hesitate to say, "I really want to know."
Please let me know.
However, depending on the number of weeks of pregnancy
You'll have to wait until it's time to make a decision.
Q3: My partner wants to know, but I don't want to know
A: It is important for couples to have frequent discussions.
Example solution:
Respect the opinions of both sides
・Wait until the week of pregnancy before deciding
・Only ask your partner to listen and keep it a secret
- Looking forward to the final birth
Any choice is correct.
Find a way that you both can agree on.
[Questions regarding the results]
Q4: They said it's a boy, but are they really sure?
A: It depends on how many weeks pregnant you are and how certain you are.
・14-16 weeks pregnant: Not reliable (false positive rate 15-20%)
・17-19 weeks pregnant: Fairly accurate but not perfect (false positive rate 5-10%)
・After 20 weeks of pregnancy: Almost certain (false positive rate 2-5%)
The wording used by the doctor is also important:
・"It's a boy" → 95% or more confidence
・"I think it's a boy" → 85-90% confidence
・"It's likely a boy" → 75-85% confidence
Q5: The gender determination has changed since last time. Which is correct?
A: The diagnosis is more accurate for those in advanced weeks of pregnancy.
Common patterns:
・14 weeks "Boy" → 18 weeks "Girl" (high chance of a girl)
・16 weeks "Girl" → 20 weeks "Boy" (high chance of a boy)
As your baby's external genitals develop with each week,
The latter judgment is more reliable.
Q6: I can't tell which part of the ultrasound image indicates the gender.
A: There is absolutely no problem.
Ultrasound photography requires specialized knowledge
It's difficult to read.
Ask your doctor to:
・Which part did you look at to make your decision?
・"Please tell me by adding an arrow."
- "Please check again next time"
There's no need to be embarrassed if you don't understand.
[Questions about twin/multiple pregnancies]
Q7: Is it difficult to determine the gender of twins?
A: It is more complicated than a single pregnancy.
Reasons for the difficulty:
Sometimes two babies overlap
- Each posture and direction is different
There are things we hide from each other
・Even with NIPT, it is difficult to determine whether twins are male or female
Judgment period:
It is usually 2-3 weeks later than in singleton pregnancies.
Q8: I have twins and I only know the gender of one of them. When will I find out the gender of the other one?
A: The timing of the test varies depending on the baby.
・An obvious pattern: A good position and the boy's characteristics are clear
- Patterns that become clear later: Hidden, or girls, so careful judgment is required
Don't rush, just check it at every checkup.
[Questions regarding preparation and mental readiness]
Q9: The gender was different from what I had hoped for. I hate myself for being disappointed.
A: Those feelings are natural and nothing to be ashamed of.
Many moms experience:
-I had an ideal family structure
- I was thinking about pairing my older child with a sibling.
・I had aspirations to be a "mom of a boy" or a "mom of a girl."
Changes over time:
・Feeling fetal movements increases your love for your baby
・The moment they are born, I feel glad that they are my child.
・When you know your child's personality, gender becomes irrelevant
Q10: Once you know the gender, when should you tell those around you?
A: It depends on your confidence and the person you're dealing with.
[Guideline for reporting timing]
Family (parents and siblings):
Report as "possibly" if confidence is 80% or higher
Close friends:
Report with 90% or higher confidence
Workplace/general acquaintances:
Reported with 95% or higher confidence or after birth
Always preface:
"I'm not sure yet though."
"Currently, there is a high possibility that it is ____."
[Question about names]
Q11: Now that I know the gender, I'd like to decide on a name. Is it too early?
A: It's good to narrow down your candidates, but be careful when deciding on them.
Recommended steps:
80% confidence level:
・Think of 3-5 name options for that gender
- Think of one or two names for the opposite gender
90% confidence level:
・Narrow down the candidates to 2-3
・Check the number of strokes and meaning in detail
95% confidence level:
・Determine the final candidates
・Prepare for birth registration
Q12: I'm worried that I've thought too much about the name and become too attached to it.
A: Loving your baby is a wonderful thing.
Points to note:
Even if the gender changes, your love for your baby will remain the same.
- Think of the name as temporary
・It's not too late to make a final decision after seeing the baby's face
There's no need to be shy about showing your love.
[Questions about medical institutions and tests]
Q13: The hospital won't tell me the gender. Can I have it checked at another hospital?
A: It's technically possible, but we don't recommend it.
reason:
・A trusting relationship with your doctor is important
・Continuous medical history is important
・Information is limited for one-off consultations at other hospitals
Alternative:
・Ask your doctor why they can't tell you
・Please ask again when the pregnancy progresses
- Understand and accept the hospital's policies
Q14: Is it more reliable to determine the gender using NIPT?
A: It is highly reliable, but you should consider the cost-effectiveness.
NIPT gender determination:
・Accuracy: 99% or more
・Time: Possible from 10 weeks of pregnancy
・Cost: 100,000-150,000 yen
Echocardiogram:
・Accuracy: 95% or more (after 20 weeks of pregnancy)
・Time: From around the 18th week of pregnancy
・Cost: Included in regular health checkups
Is a 10-week difference worth $1,400?
Please think carefully before making a decision.
[Other questions]
Q15: I'm confused because the gender superstition doesn't work.
A: Enjoy jinxes as entertainment.
The reality of the jinx:
There is little medical evidence
・The probability of winning is about 50% (same as coins)
・Only the successful experiences are memorable
Correct Source:
・Diagnosis by an obstetrician-gynecologist
・Echocardiogram
・NIPT (if desired)
Jinxes are used to create conversation and have fun.
I would recommend not taking it seriously as a basis for making decisions.
[Message from an obstetrician-gynecologist]
Through these questions, I feel
The deep love that mothers have for their babies .
I'm also curious about gender,
I also want to be prepared,
I want to think of a name,
It's all an expression of love .
But sometimes you have to stop and think.
"Will you love your baby more once you know the gender?"
"Would you love it less if you didn't know the gender?"
I'm sure the answer is "no."
Gender determination is the first step to meeting your baby.
It makes it more fun
It's a "bonus ."
Whatever the outcome,
Whatever questions or concerns you may have,
The baby growing lovingly in your belly
The feeling of cherishing
Above all else, cherish it.
The latest gender determination technology in 2025 and future prospects
The potential of AI diagnosis and 3D/4D ultrasound
The impact on mother and baby
An obstetrician-gynecologist's vision of the ideal future
"Will we ever see an era where AI can determine gender?"
"With a 4D ultrasound, you can get a more accurate picture, right?"
Recently, I was asked this question during a prenatal checkup.
I'm receiving more and more.
It is true that medical technology is advancing rapidly.
Revolutionary changes in the field of gender determination
It's starting to happen.
As an obstetrician-gynecologist, I would like to use these latest technologies.
From actual experience,
We will talk about current technology and future prospects .
[Latest technology status as of 2025]
1. AI-assisted diagnostic system
Current adoption: Limited
In some university hospitals and advanced medical institutions,
Utilizing AI (artificial intelligence)
Trial operation of a fetal diagnostic system has begun.
How the AI system works:
Training data:
Tens of thousands of echo images and
The AI learns the results of these judgments.
Judging process:
1. AI analyzes echo images
2. Automatic detection of gender characteristics
3. Display confidence numerically
4. The doctor makes the final decision
Actual accuracy:
・After 18 weeks of pregnancy: 95-98%
・15-17 weeks of pregnancy: 85-90%
・Before 14th week of pregnancy: 70-80%
Current limitations:
・Depends on the quality and quantity of training data
Difficult to deal with rare cases
The final decision must be made by a doctor
2. High-resolution 4D echo technology
Differences from previous versions:
Conventional 2D echo:
Black and white flat image
Resolution is limited
Latest 4D Echo:
Real-time stereoscopic images
High resolution for detailed viewing
Effect on gender determination:
merit:
・Enabling three-dimensional observation of external genitalia
- Check simultaneously from multiple angles
- Even minute structures can be observed
・Improved confidence in judgment
limit:
・It depends on the baby's position
・Restrictions based on pregnancy weeks remain unchanged
・High cost (additional 50,000-100,000 yen)
Actual experience:
"When I looked at it with a 4D ultrasound, I could see the baby's genitals.
It looked very three-dimensional and gave me confidence.
But in the end, I think a regular ultrasound would have been enough to tell."
(P, 34 years old, gave birth to a girl)
3. Advances in NIPT Technology
Traditional NIPT:
・Test target: 3 chromosomal abnormalities
Gender determination: secondary information
・Cost: Around 200,000 yen
Latest NIPT Plus:
・Test target: whole chromosome + microdeletion
・Gender determination: Higher accuracy
・Cost: 150,000-180,000 yen
Technological advancements:
・Test accuracy: 99.9% or more
・Period when it can be determined: From 9 weeks of pregnancy
・Results acquisition time: 5-7 days (previously 10-14 days)
[Actual effects of new technology]
Changes I have noticed as an obstetrician-gynecologist:
1. Improved judgment accuracy
Previously (around 2020):
・False positive rate at 18 weeks of pregnancy: 8-10%
・Difficult to judge cases: 15-20%
Present (2025):
・False positive rate at 18 weeks of pregnancy: 3-5%
・Difficult to judge cases: 8-10%
The accuracy is clearly improved.
2. Early decision-making
Conventional:
A definite diagnosis is made after the 20th week of pregnancy.
the current:
High-precision equipment can detect pregnancy even at 17-18 weeks
Determination can be made with over 90% confidence
3. Reduction in difficult-to-diagnose cases
With AI assistance:
Don't miss even the smallest features
・Objective criteria for evaluation
・Reducing the difference in experience among doctors
[Challenges and limitations of new technology]
1. Cost Issues
Cost of modern technology:
・AI diagnosis: +30,000-50,000 yen
・4D ultrasound: +50,000-100,000 yen
・Latest NIPT: 150,000-180,000 yen
Current insurance coverage:
These technologies are
"There is no medical necessity"
Remains uninsured
For many pregnant women
The reality is that the economic burden is huge.
2. Excessive reliance on technology
Problematic cases:
・Assuming that "It's an AI decision, so it's absolutely correct"
Not understanding the limitations of technology
・Neglecting dialogue with doctors
Don't forget:
Technology is a tool,
The final decision is
He is an experienced doctor.
3. Widening digital divide
Current situation:
・Large urban hospitals: Use of the latest technology
・Local clinics: Continue with conventional technology
・Differences in options depending on economic power
Equality in healthcare
There are challenges from that perspective.
[Outlook for the next five years (2025-2030)]
1. Standardization of AI diagnosis
Expected changes:
・Population rate of AI systems: Current 5% → 50%
・Judgment accuracy: Current 95% → 98%
・Cost: Reduced to 1/3 of current cost
Conditions for realization:
・Approved by the Ministry of Health, Labor and Welfare
・Technology development for medical device manufacturers
・Establishment of a training system for doctors
2. Possibility of at-home testing
Technologies under development:
Portable ultrasound device:
・Smartphone connectivity
・AI automatic analysis
・Remote consultation with a doctor
Challenges to realization:
・Ensuring medical safety
・Who is responsible for diagnosis?
・Response in case of incorrect judgment
3. Advances in personalized medicine
Future Gender Determination:
・The best test method for pregnant women
- Judgment taking into account past pregnancy history
・Calculation of confidence by integrating risk factors
[An obstetrician-gynecologist's vision of the ideal future]
Technical ideals:
1. Accessible technology
・Reduced cost burden through insurance coverage
- Technology dissemination without regional disparities
・Simple and easy-to-use system
2. Near 100% accuracy
・Over 95% accuracy at 15 weeks pregnant
・Eliminating difficult-to-judge cases
・Technique that is not affected by posture or number of weeks
3. Optimal collaboration between doctors and technology
・AI provides objective data
・Comprehensive judgment by a doctor
・Easy-to-understand explanations for pregnant women
Ethical ideals:
1. The inherent value of gender determination
With advances in technology,
Even if gender determination becomes easier,
It is important not to lose sight of its inherent value .
Intrinsic value:
Prepare your family
- Deepen the bond with your baby
- Increase the enjoyment of pregnancy
Things you shouldn't lose sight of:
Your baby's health is your top priority
- Individuality is more important than gender
Parental love has no conditions
2. Eliminate gender bias
Even as technology advances,
"Because it's a boy, it's ____" "Because it's a girl, it's
This stereotype should be eliminated.
Ideal Future:
・A society that values individuality regardless of gender
・A child-rearing environment that accepts diversity
・Gender determination should be used appropriately as "reference information"
[Message to pregnant women]
Don't be swayed by technology
No matter how much technology advances,
The most important thing remains the same.
The unchanging truth:
・Love for the baby growing in the womb
・Wish for healthy growth
Deepening family ties
Gratitude for new life
No matter how advanced sex determination technology becomes,
To these feelings
No skill required.
Technology is a "means" and not an "end"
Don't forget that,
A pregnancy that suits you
I hope you will cherish your time here .
The latest technology,
The old-fashioned ultrasound examination
The fun before birth
Any choice,
Happy moments for mom and baby
It's a lovely way to add color .
No matter how convenient the future may be,
Nothing beats a mother's love
Because it doesn't exist in this world.
What moms can do for their precious children
Regardless of gender, a baby will grow healthy in the womb.
He is the most beloved being in this world.
The beating of a tiny heart, the first feeling of fetal movement...
All of these are miraculous moments that connect mother and baby.
Gender determination is a way to enrich that happy time.
It's a form of enjoyment.
Even with the latest technology advancements,
Even if you choose the old-fashioned way,
Whatever the outcome,
Babies are born surrounded by their mother's love
I'm sure you'll live a happy life.
A healthy pregnancy and
Meeting a healthy baby
I pray for you from the bottom of my heart.
What moms can do for their precious children
Regardless of gender, a baby will grow healthy in the womb.
He is the most beloved being in this world.
The beating of a tiny heart, the first feeling of fetal movement...
All of these are miraculous moments that connect mother and baby.
Gender determination is a way to enrich that happy time.
It's a form of enjoyment.
Whatever the outcome,
Babies are born surrounded by their mother's love
I'm sure you'll live a happy life.
A healthy pregnancy and
Meeting a healthy baby
I pray for you from the bottom of my heart.