The formation of the fetus's gender occurs at the moment the egg and sperm meet. According to the principle: an egg carrying the X chromosome meets a sperm carrying the X chromosome, forming an XX zygote – female gender. Conversely, an egg carrying the X chromosome meets a sperm carrying the Y chromosome, forming an XY zygote – male gender.
Although the formation of the fetus's gender occurs from the moment the egg and sperm meet, it is not until the 9th week of pregnancy that the fetus's genital organs develop differently, allowing detection via ultrasound from the 12th week onwards.
1. The process of forming a female fetus's gender
When an egg carrying the X chromosome meets a sperm carrying the X chromosome, an XX zygote is formed, meaning the fetus's gender is female. Under the influence of female sex hormones (mainly the presence of Estrogen), the SRY testis-determining gene is inactivated, leading to the development of external genitalia: The genital tubercle appears between the two legs and develops into female genitalia, also known as the clitoris. Simultaneously, the urogenital folds on both sides of the clitoris form the inner labia (labia minora), opening the vagina. Notably, these folds also create the pelvic region by connecting at the bottom. The outer labia, also known as the labia majora, are formed by the enlargement of the Labiosrotal folds.
When the fetus's gender is female, the ovaries will fully develop by the 22nd week of pregnancy and move from the abdomen to the pelvis, initially containing about 6 million eggs. By the time the baby is born, this number will decrease to 1 to 2 million eggs, and by puberty, the number of eggs will be around 300,000 to 400,000.
2. The process of forming a male fetus's gender
The male fetus's gender will form external genitalia due to the presence of the male sex hormone Dyhydroterstoterone (DHT) produced by the testes. An X chromosome and a Y chromosome will produce testosterone, promoting the development of genital tissue into male genitalia. By the 12th week of pregnancy, the genital tubercle will develop into the penis and elongate, with the foreskin also forming at this time. The shaft of the penis is formed as the two urogenital folds move closer together. The scrotum (where the testes are housed) is formed as the Labiosroltal folds meet, with the Raphe line being the junction between these two folds. The testes are formed in the abdomen and will move down to the scrotum permanently in the 7th or 8th month of pregnancy.
3. Factors affecting the formation of the fetus's gender
Science has proven that the father completely determines the fetus's gender. However, the timing of intercourse, the fertilization environment within the mother's body, and the timing of fertilization are also factors that directly impact the fetus's gender.
An alkaline environment in the mother's body is ideal for the development and fertilization of Y sperm. Therefore, in the first 3 months, if the mother tends to consume foods rich in alkaline substances such as sausages, oranges, and melons, the fetus's gender is likely to be male. Conversely, if the mother supplements with foods rich in magnesium and calcium such as kale, soybeans, tomatoes, carrots, and eggs, the vaginal environment will be acidic, ideal for the development of X sperm, and the fetus's gender is likely to be female.
As men age, the quantity of sperm decreases, and the quality of Y sperm decreases more than X sperm. Additionally, the aging process in women can affect the formation of the fetus's gender because age impacts the secretion of alkaline compounds in the uterus.
The closer the timing of intercourse is to ovulation, the higher the likelihood of having a boy, and conversely, intercourse further from ovulation increases the likelihood of having a girl.
4. How to determine the gender of the fetus?
In reality, there are many methods that can be used to determine the gender of the fetus, but all are just guesses, passed down by word of mouth. Nowadays, with the development of modern medical technology, there are medical techniques that help accurately determine the gender of the fetus, such as: ultrasound (most accurate results from the 18th to 20th week of pregnancy), chorionic villus sampling (in addition to determining the gender of the fetus, this technique also helps detect chromosomal abnormalities in the fetus), and blood tests.
Knowing the formation of the fetus's gender will help parents have a better way to care for and prepare to welcome their baby. However, the most important thing is still the health of the fetus, a safe birth, and whether the baby is a boy or a girl, they are still an angel that needs to be cherished and carefully cared for.
Usually, to determine the gender of the fetus, pregnant women often use the ultrasound method. However, the accuracy will depend greatly on modern equipment and the doctor's expertise. Therefore, you should go to reputable medical facilities for examination.
Vinmec International General Hospital is a high-quality medical facility highly rated by customers for its quality of examination and treatment as well as professional services. Vinmec has the most modern equipment system, with the most advanced ultrasound machines in the world and a team of experienced obstetricians in diagnosing the gender of the fetus.
In addition, to fully protect the health of both mother and baby, Vinmec offers a variety of comprehensive maternity packages. With this package, pregnant women will have regular prenatal check-ups with specialists. Perform prenatal and postnatal screening tests for the baby. During pregnancy, if the pregnant woman encounters any abnormal health issues, doctors will provide consultation and treatment with specialists. After each examination, doctors will analyze ultrasound and test results and advise on health care, nutrition, and rest suitable for each pregnant woman, helping the mother stay healthy and the fetus develop well and evenly.
If you need to use maternity services at Vinmec, please register directly on the website to be served.
To arrange an appointment, please call HOTLINE or make your reservation directly HERE. You may also download the MyVinmec app to schedule appointments faster and manage your reservations more conveniently.
