B ultrasound shows that the baby girl is a boy

B-ultrasound is the most common way to check the sex of a fetus. The accuracy of this method is relatively high, but errors may occur. If the B-ultrasound examination shows that the baby is a girl, but the baby is born a boy, it may be because the fetus's genitals have not yet formed completely, and the baby's sexual characteristics are just blocked, which will also affect the results of the B-ultrasound examination, because the accuracy rate of B-ultrasound for female babies is only 80%.

What if a girl gave birth to a boy through ultrasound?

Determining the sex of the fetus through B-ultrasound is a relatively scientific method with a relatively high accuracy rate. B-ultrasound determines whether it is a boy or a girl by observing the fetus's genitals. Generally, the fetus's genitals will be formed around 16 weeks of pregnancy, which means that the gender of the fetus can be determined through B-ultrasound after 4 months of pregnancy.

However, due to various considerations, our country has explicitly prohibited doctors from disclosing the gender of the fetus to pregnant women or their families. If the B-ultrasound determines that the baby is a boy, then the accuracy rate can be about 95%, because in very rare cases, the B-ultrasound will mistake the baby's umbilical cord for the sexual characteristics of a boy, thus causing a misjudgment; if the B-ultrasound determines that the baby is a girl, then the accuracy rate can be about 80%, because there is a 20% chance that the baby's sexual characteristics are blocked, thus causing a misjudgment.

Who determines the sex of the fetus

Female sex chromosomes are XX, and they can only form one type of egg in a month; male sex chromosomes are XY, and they can form two types of sperm, X-containing sperm or Y-containing sperm. The sperm and egg combine and fuse into one, becoming a fertilized egg. In this way, the 23 chromosomes in the sperm and the 23 chromosomes in the egg form 23 pairs of chromosomes.

If the X sperm combines with the egg, the pair of sex chromosomes in the fertilized egg will be XX, and the fetus will develop into a female; if the Y sperm combines with the egg, the pair of sex chromosomes in the fertilized egg will be XY, and the fetus will develop into a male. From this we can see that whether the baby is a boy or a girl is determined by whether the sex chromosome carried by the man's sperm is X or Y, and has nothing to do with the egg. At the time of fertilization, the combination of the male's sperm and the female's egg is random and the chances are equal, which means that there is a 50% chance of forming an XX zygote and a 50% chance of forming an XY zygote.

Now everyone understands why a boy is born when an ultrasound shows a girl. The problem lies in whether the fetus is too small or the gender characteristics are obscured during the ultrasound examination.

Early symptoms of pregnancy with a boy

1. Belly shape: Pregnant women carrying boys have pointed and convex bellies.

2. Nipple changes: If the left nipple of a pregnant woman is darker or even almost black, it can be determined that she is pregnant with a boy.

3. Skin and appearance: If a pregnant woman's appearance becomes uglier, her skin becomes rough, or even her face is covered with acne, she may be pregnant with a boy.

4. The body shape of pregnant women: If the belly, chest and other parts of the pregnant woman's body gain weight significantly, she may give birth to a boy; if the waist, hips and buttocks gain weight significantly, she may give birth to a girl.

5. Pregnant woman’s belly button: If a pregnant woman’s belly button is protruding, she is pregnant with a boy.

6. Pregnancy line: If the pregnancy line above the navel is straight, thin, and reaches between the two breasts, it means you are pregnant with a boy.

7. Pregnant women’s taste: Pregnant women carrying boys will have a sharp increase in appetite after pregnancy, and they like to eat a lot of their favorite foods.

8. Morning sickness: If a pregnant woman does not experience morning sickness in the first three months of pregnancy, she is likely to give birth to a boy.

9. Fetal heart rate: The fetal heart rate of a boy is lower than that of a girl. If the pregnant woman measures the fetal heart rate and finds it is around 140, it means she is pregnant with a boy.

10. Fetal movement: If a pregnant woman feels that the fetus is often "exercising" in her belly, she is likely to be pregnant with a boy. Early fetal movement also means that you may be pregnant with a boy. Girls are those who have obvious fetal movement when hearing the melody of music, while boys are those who just appreciate it quietly.

11. Fetal position: If the fetus is in the upper position, it is a girl; if the fetus is in the lower position, it is a boy; if the fetus likes to stay on the left side of the abdomen, it is a girl; if the fetus likes to stay on the right side, it is a boy.