"Looking at the data of the Gestational Sac on the B ultrasound, you can know the baby's gender in advance", is this true?

True points:

1. The gestational sac in the first trimester is very soft, and any pressure can change its shape. Factors such as uterine fibroids and the degree of bladder filling can also affect the shape of the gestational sac. At different times, the shape of the gestational sac also changes greatly, and it is impossible to judge the sex of the fetus.

2, "sour children and hot women", "belly tip is a boy, belly round is a girl" and other folk sayings are also unreliable, can accurately determine the sex of the fetus is the fetal chromosome and B ultrasound examination. However, parents need to know that it is illegal to identify the sex of the fetus during pregnancy.

Verifier: Guo Xushu Attending Physician of the Department of Obstetrics and Gynecology, Affiliated Hospital of Sun Yat-sen University

Recently, a self-media article has been widely circulated, to the effect that after pregnancy, the doctor does not tell the sex of the fetus not to be afraid, parents can easily judge whether the fetus is male or female through the 3 data of the gestational sac on the B ultrasound single. If 2 of the 3 data of the gestational sac are similar, and the 3rd data is about 1 times smaller than the first two, then the possibility of conceiving a boy is greater; if the 3 data are decreasing, the possibility of conceiving a girl is greater.

In order to prove its credibility, the article also deliberately emphasizes the following points:

1.B ultrasound needs to hold urine, which will affect the data, and the general yin ultrasound is more accurate.

2. The data on the size of the gestational sac is preferably not more than 8 weeks, and the data for about 40 days is more accurate.

3. The gestational sac data must be 3, just like the length, width and height, 3 data are needed to judge, only 2 data are inaccurate.

As a professional, I can only tell you that moms who are eager to know whether their baby is male or female, don't believe it. This nonsense article is completely unreliable!

First, what is the pregnancy sac

The gestational sac is a primitive placental tissue, a small embryo wrapped in amniotic membranes and a network of blood vessels. At 4-5 weeks of menopause, transvaginal ultrasound examination reveals that there are round or oval gestational sacs in the uterine cavity of the pregnant mother. At 5 weeks of menopause, germ and primitive heart canal beats can be seen in the gestational sac.

At this time, we can judge whether it is an intrauterine pregnancy and whether the fetus is a live fetus according to the gestational sac and the baby's heartbeat. However, if you are doing a transabdominal ultrasound examination that requires holding urine at this time, the time to see the gestational sac may be delayed by about 1 week.

The gestational sac is very small in the early stages of pregnancy, and at about 35 days, it is only about 4 mm. With the prolongation of pregnancy, the gestational sac in the first trimester will also grow rapidly, and by the time of 6 weeks of pregnancy, the average diameter of the gestational sac can grow to 11-21 mm.

Second, the shape of the gestational sac is affected by too many factors, and the changes in different periods are great, and it is impossible to judge the sex of the fetus

When measuring the size of the gestational sac, the B ultrasound doctor will generally measure the longitudinal diameter, transverse diameter and anteroposterior diameter of the gestational sac, and then take the average of the 3 values to measure the size of the gestational sac. If the values of the 3 data are close, the shape of the gestational sac will be close to the circle; if the values of the 3 data are about doubled, the shape of the gestational sac will be close to the oval. The three data mentioned in the above-mentioned online article refer to the three data of the longitudinal diameter, transverse diameter and anteroposterior diameter of the gestational sac.

First of all, the conclusion is that some of the gestational sacs are round and some are oval, which is a normal phenomenon and has nothing to do with the sex of the baby.

Because in the first trimester, the embryo is still very small, so the main component of the gestational sac is amniotic fluid. We can think of the first trimester sac as a ball of water filled with fluid. The amniotic membrane on the outside of the gestational sac is very thin and very soft, and any pressure can change its shape. Therefore, factors such as the gravity of the gestational sac itself, the size of the uterine cavity, the shape of the uterine cavity and the location of the embryo implant will all affect the shape of the gestational sac. In addition, factors such as uterine fibroids and the degree of bladder filling can also affect the shape of the gestational sac.

The gestational sac itself can also change. According to the pattern of the development of the gestational sac itself, the gestational sac can be shown by ultrasound after 5 weeks of pregnancy, initially round, but because the longitudinal diameter and transverse diameter of the gestational sac develop rapidly than the anterior and posterior diameters, it will begin to become oval at 7-8 weeks. Therefore, the earlier the B ultrasound examination time, the closer the 3 data values of the gestational sac will be; the later the B ultrasound examination time, the 3 data values of the gestational sac may be about doubled.

If the net article is true - 2 values are close, the third data is about 1 times smaller than the first two, it is a boy; 3 data is gradually decreasing, it is a girl. Then in reality, there will be a previous check out of the value indicating that the fetus is a "girl"; when the later review, the fetus has become a "boy" ridiculous situation.

The statement in the web article "the data on the size of the gestational sac is best not more than 8 weeks, because the data will be more accurate" is also wrong. Because it is also within 8 weeks, 5 weeks and 7 weeks, the shape and value of the gestational sac will change significantly, and there is no basis for the statement that the data is more accurate.

Third, the "sour child and hot woman" and other statements to determine the sex of the fetus are also unreliable, and chromosome and B ultrasound examination can be accurately judged

Many pregnant mothers want to know whether they are pregnant with a boy or a girl during pregnancy, except that some people have a patriarchal mentality, and more people may just be purely curious, or want to prepare items according to the sex of the baby.

As a mother of two children, I can understand the idea of a pregnant mother who wants to know everything about the baby in her belly during pregnancy, and what mother would not be curious about the gender of the baby in her belly?

But I still want to tell you "sour and spicy girl", "the tip of the belly is a boy, the belly round is a girl", "the mother's belly hair is a boy, not hair is a girl", "the mother's pregnancy body is not out of shape is a boy, the body shape is a girl", "the baby's fetal movement is a boy, the power is a girl", "the pregnant mother's navel is a boy, the navel is a girl"... These local methods of oral propaganda are all unreliable!

So what is the reliable solution? The method of accurately determining the sex of the fetus is the fetal chromosomal examination and the ultrasound examination. In the case of medical needs, we can check the fetal chromosomes through non-invasive DNA, amniocentesis, umbilical cord blood puncture and other methods, at this time, whether the child is a boy or a girl, you can know it by checking.

In addition, after 3-4 months of pregnancy, the external genitalia of the fetus can be observed by ultrasound examination, and it can also be determined whether the child is a boy or a girl. However, this method has a certain error due to factors such as the child's development and fetal position.

Finally, parents need to know that although you want to know the sex of your child, under mainland law, it is illegal to identify the sex of the fetus during pregnancy, so even if the ultrasound doctor can see the sex of the baby during the examination, they will not tell you.

Every child is a gift from God, and when they are conceived in our bodies, we wait patiently, feel with our hearts, and wait for the moment the baby is born to "open the blind box", such a journey will also bring unexpected happiness.