Discover if it's possible to choose the desired gender of a baby. Learn about various gender selection methods, including the Percoll method, timing, and dietary approaches, as well as the latest advancements in non-invasive prenatal testing (NIPT). Understand the success rates and important considerations for gender selection.
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Summary of this article
There is no guaranteed method to ensure the birth of a boy or girl. Even with the use of the Percoll method, which involves selecting sperm to influence the baby’s sex, the success rate is said to be around 60-70%. While the most important thing is the safe birth of the baby regardless of gender, it is crucial for couples to have thorough discussions and decide together if they want to make any efforts to have a child of their preferred gender.
The Gender of the Baby
First-time expectant mothers, as well as those expecting their second or third child, often have thoughts like “I hope it’s a boy” or “I hope it’s a girl.”
While more clinics are now providing information on the baby’s gender during pregnancy, some parents prefer to keep it a surprise until birth.
Whether it’s a boy or a girl, a child is always precious, and finding out the gender at birth can be even more emotional.
Additionally, imagining how you might raise a boy or how you might dress a girl in cute clothes is part of the joy of pregnancy.
In this article, we delve into the topic of a child’s gender, sharing insights from experienced mothers.
If You Could Only Have One Child, Boy or Girl?
According to a survey reported by the Institute of Statistical Mathematics in 2013, in response to the question “Do you want a boy or a girl?”, more people answered “boy” in 1988. However, from around 1993 for the next 20 years, the number of people who wanted a girl increased.
Additionally, in a survey conducted by Sankei Living Newspaper in 2018, 66% of respondents said, “If I could only have one child, I would want a girl!”, followed by “either is fine” at 20%, and “I want a boy!” at 13%.
Combining these results with the survey from the Institute of Statistical Mathematics, it seems that there is currently a trend of more people preferring to have a girl.
Reasons for Preferring a Girl
There are various opinions online about the gender of their expected child. Here are some reasons given by people who prefer having a girl:
- There are many cute clothes available, making it fun to dress them up.
- I’ve heard that girls are easier to raise.
- My friends told me, “It takes a lot of energy to raise a boy!”
- With a girl, you can enjoy shopping and having lunch together.
- I dream of having a relationship with my daughter like that of friends.
- I believe a girl can have a more enjoyable life.
- I can comfortably play with and take care of my daughter’s grandchildren.
- When it comes to future care, girls are more reliable.
- Sons tend to become distant after marriage, but daughters are more likely to return home often.
Reasons for Preferring a Boy
Here are some opinions from those who prefer having a boy:
From women:
- Boys require more attention than girls, but that makes them even more lovable.
- When they are small, a son feels like a little boyfriend.
- My husband is an outdoorsy person, so having a boy to join him would be great.
From men:
- I can play with him both at home and outside.
- I want to play catch and other games together.
- A son feels like a comrade within the family.
- I want my son to accomplish what I couldn’t.
- He might take over my job in the future.
It seems that the desire to have a boy is more common among men than women.
What do you think? Everyone seems to be looking ahead to the future. Having a boy or a girl brings different considerations when thinking about the long term.
However, for parents, both boys and girls are precious. Boys and girls both typically go through rebellious phases during adolescence. It might be best to view this as a natural part of their growth and just wait for the storm to pass.
Is It Possible to Choose the Desired Gender?
There are mixed opinions about the practice of gender selection, but some people may want to try it if possible.
With current medical technology, there is no method to guarantee 100% success in gender selection, making it impossible to ensure a specific gender. However, there are several methods believed to increase the probability of having a child of the desired gender.
Some obstetrics and gynecology clinics provide gender selection guidance, with reported success rates generally around 70-80%. Given that the natural probability of having a baby of the desired gender is 50%, this is a significant increase.
However, it’s important not to have excessive expectations about gender selection. It’s best to approach it with the mindset of “I would prefer a boy if possible” or “I would prefer a girl if possible.”
What is Gender Selection?
It refers to couples who wish for a child of a specific gender and take measures using various methods to increase the chances of having a baby of their desired gender.
How is the Baby’s Gender Determined?
Before attempting gender selection, it’s important to understand when and how a baby’s gender is determined.
Human gender is determined by the combination of two sex chromosomes.
- Males have one “X chromosome” and one “Y chromosome.”
- Females have two “X chromosomes.”
Sperm and eggs each contain only one sex chromosome.
- Sperm carries either an “X chromosome” or a “Y chromosome.”
- Eggs carry one “X chromosome.”
The moment a sperm meets an egg, i.e., at fertilization, the two chromosomes combine, and the gender is determined.
- If an “X sperm” fertilizes the egg ⇒ The sex chromosomes are “XX,” resulting in a girl.
- If a “Y sperm” fertilizes the egg ⇒ The sex chromosomes are “XY,” resulting in a boy.
Gender selection is based on controlling fertilization according to this principle.
In fact, “X sperm” and “Y sperm” have slightly different characteristics. By creating an environment suitable for each, the probability of having a baby of the desired gender can be increased.
Gender Selection by Shettles Method
Method for Having a Boy
The “Y sperm,” which is necessary for conceiving a boy, has the following characteristics:
- A short lifespan of about one day
- Survives better in an alkaline environment
To create an environment where Y sperm can meet the egg and fertilize it more easily, the following two factors are important:
- Having sex on the day of ovulation (timing method)
- Making the vaginal environment more alkaline
Normally, a woman’s vagina is acidic to prevent bacteria from entering. As ovulation approaches, it becomes more alkaline, but there are methods to enhance this alkalinity:
- Inserting an alkaline gel called “Green Gel” into the vagina during sex
- Achieving orgasm during sex (when a woman orgasms, alkaline mucus is secreted from the cervix)
- Using supplements that contain calcium phosphate
By calculating the ovulation day from the previous menstrual cycle and trying these methods, it is said that the chances of having a boy can be increased.
Method for Having a Girl
The “X sperm,” which is necessary for conceiving a girl, has the following characteristics:
- A longer lifespan of about 2-3 days
- Survives better in an acidic environment
To create an environment where X sperm can meet the egg and fertilize it more easily, the following two factors are important:
- Having sex two days before ovulation (timing method)
- Making the vaginal environment more acidic
As ovulation approaches, the vaginal environment becomes more alkaline, but there are methods to make it more acidic:
- Inserting an acidic gel called “Pink Gel” into the vagina during sex
- Avoiding orgasm during sex (when a woman reaches orgasm, alkaline mucus is secreted from the cervix)
By calculating two days before the ovulation day from the previous menstrual cycle and trying these methods, it is said that the chances of having a girl can be increased.
Are There People Unsuitable for This Method?
This method of gender selection can activate either X sperm or Y sperm while simultaneously weakening the activity of the other, which can reduce the overall pregnancy rate.
Therefore, it is not suitable for people who have difficulty conceiving due to factors such as age or physical condition, or those undergoing fertility treatments.
Additionally, since the timing of sex is crucial, the cooperation of the partner is necessary.
If the couple does not agree, it may be challenging to attempt gender selection.
Furthermore, it is not recommended for those who are not willing to accept a baby of the opposite gender, as gender selection should not lead to the selection of life based on preference.
Gender selection should be approached with the understanding that the baby, whether a boy or a girl, will be cherished and nurtured with care.
Artificial Insemination and Gender Selection
There is a gender selection method called the Percoll method, which uses artificial insemination. The Percoll method takes advantage of the fact that X sperm are heavier than Y sperm.
During artificial insemination, the collected male sperm is centrifuged, causing the heavier X sperm to settle at the bottom layer and the lighter Y sperm to rise to the top layer.
Using the sperm from the bottom layer for artificial insemination increases the likelihood of having a girl, while using the sperm from the top layer increases the likelihood of having a boy.
However, since it is not possible to completely separate X sperm and Y sperm using this method, it does not guarantee 100% success in gender selection.
It is important to approach this procedure with the understanding that the baby will be cherished and nurtured, regardless of the gender.
Gender Selection by Calendar and Diet
There are also methods of gender selection based on calendars.
One such method is the Chinese gender prediction calendar, created approximately 700 years ago based on birth records of boys and girls compiled by Chinese scientists. This method is used to predict the baby’s gender. Another similar method is the Brazilian gender selection calendar, although its origin and background are unclear.
In any case, the calendar-based gender selection methods are not based on scientific evidence, so they should be considered more as fortune-telling or superstitions and used only as a reference.
Another method involves attempting gender selection through diet. By consuming foods that are acidic or alkaline, it is believed that you can alter the body’s pH to favor the desired gender.
However, the human body has mechanisms to maintain a stable pH level, making it difficult to change the body’s pH through diet. Therefore, dietary methods for gender selection should also be considered as references rather than reliable methods.
When Can You Find Out the Baby’s Gender?
The gender of the baby is determined during prenatal checkups through ultrasound examinations, where the external genitalia are observed.
Finding out the gender can give a renewed sense of “I’m going to be a mom!” However, the differences in external genitalia become clear around 20-23 weeks (6 months) of pregnancy.
During an ultrasound exam, a specialized device sends out ultrasonic waves to the mother’s belly. The reflected signals are then converted into images displayed on a monitor.
This test is very safe with no concerns about radiation, but sometimes the baby’s position may prevent clear imaging of the external genitalia. Nevertheless, repeated ultrasound exams will eventually reveal the baby’s gender.
Ultrasound technology has advanced, and now some clinics offer 3D ultrasounds that can show the baby in three-dimensional detail, or the latest 4D ultrasounds that can observe the baby’s expressions and movements.
Seeing your baby yawn or suck their thumb in the womb makes them even more precious.
Determining Gender with NIPT (Non-Invasive Prenatal Testing) Immediately After Pregnancy Confirmation by Ultrasound
If you want to know the gender of your baby earlier, you might consider ” NIPT (Non-Invasive Prenatal Testing),” which can be done immediately after pregnancy is confirmed by ultrasound.
Until now, prenatal diagnostics such as chorionic villus sampling (CVS) and amniocentesis have been performed. However, these procedures involve inserting a needle into the mother’s abdomen, posing a risk of miscarriage and placing a significant burden on the pregnant woman.
As a result, NIPT (Non-Invasive Prenatal Testing) has gained attention due to its extremely high negative predictive value (the probability that a person with a negative test result is truly negative). NIPT only requires a blood sample, which means it imposes minimal burden and infection risk on the mother.
If the NIPT result is negative, it indicates a very low probability of the target diseases, potentially eliminating the need for riskier procedures like CVS or amniocentesis.
Moreover, NIPT can also determine the baby’s gender.
NIPT can reveal the gender approximately two months earlier than an ultrasound. While an ultrasound can generally determine the fetus’s gender around 20 weeks of pregnancy, NIPT can provide this information as soon as pregnancy is confirmed via ultrasound. Those interested can opt for NIPT immediately after pregnancy is confirmed by ultrasound to test for chromosomal abnormalities and determine the baby’s gender.
Why Gender Can Be Determined by NIPT
In NIPT (Non-Invasive Prenatal Testing), fetal DNA fragments present in the mother’s blood are collected and analyzed by a machine (sequencer) to check for the possibility of chromosomal disorders.
The difference between boys and girls is determined by their sex chromosomes. NIPT can determine the baby’s gender by analyzing whether the sex chromosomes are XY (boy) or XX (girl).
However, certified NIPT facilities do not handle gender determination. If you want to know the gender through NIPT, you should undergo the test at a non-certified facility that offers the gender determination option.
Conclusion
We have explained the methods of gender selection.
There is no guaranteed method to ensure the birth of a boy or girl. Even using the Percoll method, which involves selecting sperm for gender selection, the success rate is said to be around 60-70%. Regardless of the gender, the most important thing is for the baby to be born healthy. Couples should have thorough discussions and decide together whether to make any efforts to have a child of their preferred gender.
【References】
- Social Facts Data Catalog – Do You Want a Boy or a Girl?
- Nikkei – What is the One-Child Policy? China’s “Gender Selection” and Unregistered Residents
Discover if it's possible to choose the desired gender of a baby. Learn about various gender selection methods, including the Percoll method, timing, and dietary approaches, as well as the latest advancements in non-invasive prenatal testing (NIPT). Understand the success rates and important considerations for gender selection.
Read more about NIPT
Article Editorial Supervisor
Dr Hiroshi Oka
NIPT specialist clinic, MD
Graduated from Keio University, School of Medicine
