Is it Possible to choose a Gender for your Baby? (*Written with Supervision of a Doctor)

When you become pregnant, you may wonder about the gender of your baby. If it were possible to have a boy or a girl, which would you prefer? Here are some reasons why you might want a girl or a boy, how gender preselection is done, and how to determine the gender/sex of your baby.

Know your baby's gender
as early as 10 weeks!

Know your baby's gender
as early as 10 weeks!

The gender of the fetus is known at 10 weeks.

What gender of the baby is of interest to you?

Pregnant women who are becoming mothers for the first time, or even for the second or third time, are probably envisioning that they would like to have a baby boy or a baby girl.

Although more and more clinics can now inform you of the gender of your baby, there are still some people who do not ask about the sex of your baby, keeping it for your enjoyment until the birth of your child.

Whether it is a baby boy or a baby girl, we think our children are adorable, and it may be more touching to know the gender when they are born.

Imagining, “If it’s a baby boy, I want to raise him like this,” or “If it’s a baby girl, I want her to wear cute clothes…” is one of the pleasures of being pregnant.

This article delves into the gender of babies being born, with some insights from experienced mothers.

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If you could have only one child, would you prefer a boy or a girl?

According to a 2013 survey reported by the Institute of Statistical Mathematics, ” Do you want a baby boy or a baby girl? ” most respondents answered “boy” in 1988, but for the past 20 years, since approximately 1993, more people have been preferring a girl.

In a survey conducted by Sankei Living Shimbun in 2018, 66% of respondents answered, “If I could have only one child, I would want a girl!” followed by 20% who said “either one” and 13% who said “I want a boy!”.

When combined with the results of a survey by the Institute of Statistical Mathematics, the trend over the past 25 years suggests that more people are hoping for girls.

ls it only in Japan that people want girls?

Why is it that more and more people are now wishing that their child should be a girl?

According to a survey conducted in 2006, many respondents in three East Asian countries (South Korea, Taiwan, and China) said they want a baby boy, especially in China, where more than double the number of respondents wanted a baby boy than a baby girl.

Under China’s ‘One-Child Policy’, many families wanted a boy as an heir, and in fact, ‘child-bearing’ was rampant. Because of this, the number of males greatly outnumbers the number of females in the younger generation.

A decade ago in Japan, many Japanese wanted a boy to ‘take over the family’, though times have changed, and the perception of an heir has probably declined.

The gender preference on the baby may be related to the political or economic/industrial structure of the country.

Is it Possible to choose a Gender for your Baby? (*Written with Supervision of a Doctor)

Why Having Girls is Better?

We have gotten a variety of opinions on the Internet about what gender the baby should have, and we will present some of them below. Let’s start with the reasons for those who said “I want a girl!”

  • “There are lots of cute clothes and fun to dress them in.”
  • “I’ve heard that girls are easier to raise.”
  • “I heard from my friends that it takes a lot of energy to raise a boy!”
  • “Girls can enjoy shopping and lunch together.”
  • “I long to be friends with my daughter.”
  • “I would enjoy my life more if I were born a girl.”
  • “I can play with and take care of my daughter’s grandchildren without worrying.”
  • “In the future, when it comes to being taken care of, a girl is more reliable.”
  • “My son will be estranged from me after marriage, but my daughter will come back to my house for some reason.”


Why Having Boys is Better?

Here are the opinions on having boys:

  • “They take more work than girls, so they are cuter.”
  • “My son will be like the tiny version of my partner.”
  • “My husband loves the outdoors, so I prefer a boy to keep him company.”

It seems that more men would like to have a boy than women.

Men say they want a baby boy who:

  • We can play together at home or outside.
  • I want to play catch, etc. with him.
  • I feel like my son is my comrade in the family
  • I want my son to be able to do what I have not been able to do.
  • I want my son to be able to take over my business in the future.

How was it? Everyone seems to be looking ahead into the future.

It seems that there are many differences between having a boy and having a girl, even looking into the future. However, for parents, it may be true that both are adorable as long as they are their own children.

Incidentally, the writer of this article experienced raising both a boy and a girl, but looking back, it was the daughter who was easier to raise.

Both boys and girls generally rebel when they reach puberty.
For boys, rebellion is harder. It may vary from person to person, but girls are more likely to rebel only verbally, which is more tolerable.

We may just have to think of rebellion as a process of growth and wait for the storm to pass.

Is it possible to have a baby of my desired gender?

Many people are “fine” with either a boy or a girl, but some would like to have both if they can.

Gender separation is not 100%, but it is technically possible.

Some obstetrics and gynecology clinics offer birth guidance, and the success rate is generally estimated to be 70-80%. Since the probability of having a baby of your desired gender is originally 50%, the success rate is considerably higher.

However, even with birth control guidance, mistakes can still occur, and you should not get your hopes up too high. It is important to be prepared for the possibility of having either a boy or a girl.

What is a Birth Segregation in the first place? How is the Gender of the Baby Determined?

Before trying to have a baby, you should first know when and how the gender of your baby is determined.

Human gender is defined by the combination of two sex chromosomes.

  • Male: X and Y chromosome
  • Female: X and X chromosome

On the other hand, sperm and eggs contain only one sex chromosome each.

  • The Sperm has either one ‘X’ or one ‘ Y’chromosome
  • The egg has one X chromosome.

Then, at the moment the sperm and egg meet, that is, when fertilization occurs, they become two, and the gender is determined.

  • X sperm with X chromosome is fertilized => ‘XX’ sex = Girl
  • Y sperm with Y chromosome is fertilized => ‘XY’ sex = Boy

Male-female separation is based on this principle to control fertilization.

In fact, the properties of “X sperm” and “Y sperm” are slightly different, and by providing the right environment for each, the probability of having a baby of the desired sex/gender increases.

How to Give Birth to a Boy?

The ‘Y sperm’ necessary to produce a boy has the following properties:

  • Has a short lifespan of about 1 day
  • Survives easily in alkaline environments

Therefore, the following two things are important in creating an environment favorable for the Y sperm to meet and fertilize the egg:

  • Have sex on the day of ovulation (Timing Method)
  • Make sure your vagina is more highly alkaline

Normally, a woman’s vagina is acidic to prevent the entry of bacteria. As the day of ovulation approaches, it becomes more alkaline, but there are ways to make it more alkaline.

  • An alkaline jelly called ‘Green Jelly’ is inserted into the vagina during sex.
  • Reaching orgasm during sex (when the woman “comes”, alkaline mucus is secreted from the cervix)
  • “Take a Phosphoric Acid, which has calcium phosphate as its main ingredient, for two months before having sex (the mechanism is unknown, but it is said that taking Phosphoric Acid produces only boys).”

Trying these will make it easier to have a boy.

How to Give Birth to a Girl?

The ‘X sperm’ necessary to produce a girl has the following properties:

  • Long life span of about 2-3 days
  • Easily survives in an acidic environment

Therefore, the following two things are important for the X sperm to meet the egg and create an environment conducive to fertilization.

  • Have sex two days before ovulation (Timing Method)
  • Make the vagina more acidic

As the day of ovulation approaches, the vagina becomes alkaline, but there are ways to make it more acidic.

  • Insert acidic jelly called ‘pink jelly’ into the vagina during sex.
  • Avoid reaching orgasm during sex (when a woman “comes” or “reaches climax,” her cervix secretes alkaline mucus.

Trying these things will make it easier to have a girl.

Is someone unsuitable for childbirth?

The fertility rate decreases because it makes either X sperm or Y sperm more active while at the same time weakening the activity of one or the other.
Therefore, it is not suitable for people who have difficulties conceiving or people who are undergoing fertility treatment due to age, physical condition, or other conditions.

In addition, since the timing of sex is important, the cooperation of the partner is necessary.
It may be difficult for “couples who are not in agreement with each other” to try for a mixed-sex pregnancy.

Moreover, it is not recommended for those who have no intention of giving birth to a baby of an unwanted sex.
This is because gender selection should not lead to the sorting out of lives.

The premise of gender selection is to take good care of the life you give birth to, whether it is a boy or a girl.


When will you know the gender of your baby?

The gender/sex of the baby is determined by looking at the external genitalia during an ultrasound examination (ultrasonography) during a maternity checkup.

When the sex of the baby is determined, you may once realize “I’m going to be a mother!” It is considered that the difference in the external genitalia becomes clear between the 20th and 23rd week (6 months) of pregnancy.

In the ultrasound examination, an ultrasound device is used to transmit ultrasound waves to the mother’s abdomen, and the reflected signals are converted into images and displayed on a monitor.

It is a safe test with no risk of radiation, but depending on the baby’s orientation, the external genitalia may not show up well. Even so, the baby’s external genitalia will become visible after several ultrasound examinations.

There are now clinics that offer 3D ultrasound, which can show the baby’s shape in three dimensions, and the latest 4D ultrasound, which can observe the baby’s facial expressions and movements.

It will be even more adorable to see your baby yawning or sucking his/her fingers inside your belly.

Gender Determination is also possible with NIPT (Non-invasive Prenatal Testing), which can be performed as early as 10 weeks of pregnancy.

If you would like to know the sex of your baby sooner, you may want to consider NIPT (Non-invasive Prenatal Testing), a test that can be performed as early as 10 weeks into your pregnancy.

NIPT (Non-invasive Prenatal Testing) is a screening test for chromosomal abnormalities based on the baby’s DNA, which is found in the mother’s blood.

Chromosomes normally reside in cells, but it has been discovered that fragments of fetal chromosomes (cell free DNA) are circulating in the mother’s blood.

NIPT (Non-invasive Prenatal Testing) is highly accurate because it analyzes this small amount of fetal DNA to check for chromosomal diseases, and it is distinctive in that it requires only a blood sample to perform the test.

Until now, prenatal diagnoses have been performed by means of chorionic villus and amniotic fluid tests, but these involve inserting a needle into the mother’s abdomen, which carries the risk of miscarriage and places a heavy burden on the pregnant woman.

However, NIPT (Non-invasive Prenatal Testing), which has an extremely high negative predictive value (the probability that a negative test result is a true negative), has been drawing attention because of its low risk of infection and low burden on the mother since the test only requires a blood sample.

If the result of NIPT is negative, there is almost no possibility of developing the targeted disorders, so there is no need to undergo a risky chorionic villus test or amniotic fluid test.

Gender determination is also possible with NIPT (Non-invasive Prenatal Testing).

Although this is just an extra benefit since it has nothing to do with the disease, NIPT (Non-invasive Prenatal Testing) can determine the gender/sex of the baby about two months earlier than the ultrasound test.

Generally, the gender of the fetus can be determined by the ultrasound test at around 20 weeks of pregnancy, but with NIPT (Non-invasive Prenatal Testing), it can be determined as early as 10 weeks of pregnancy. If you are concerned about the gender of your baby, you may wish to have the NIPT (Non-invasive Prenatal Testing), which is available from 10 weeks of pregnancy, to determine the baby’s gender along with the test for chromosomal abnormalities.

Pregnancy and childbirth are exciting life events that can be described as the most significant in your life.

For sure, you can’t wait to meet your adorable baby.

Whether you are having a boy or a girl, enjoy raising your child and build a strong relationship of trust between you and your child.

I, myself, want to guide my child so that he or she can live a happy life.

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When you become pregnant, you may wonder about the gender of your baby. If it were possible to have a boy or a girl, which would you prefer? Here are some reasons why you might want a girl or a boy, how gender preselection is done, and how to determine the gender/sex of your baby.

Read more about NIPT

Read more about NIPT

Article Editorial Supervisor

Dr Hiroshi Oka

Dr Hiroshi Oka

NIPT specialist clinic, MD

Graduated from Keio University, School of Medicine



  1. 染色体異常の種類について