How to determine the accuracy of Down syndrome screening for male and female

Recently, a method of predictive analysis for fetal gender identification has become popular among mothers on the Internet. I heard that you can tell the gender of the baby in your belly just by looking at the Down syndrome screening report. So how do we determine the gender of the baby based on the Down syndrome screening results? Accuracy? Let’s take a look together!

First look at the MOM value of b-HCG:

Below 0.4, most of them are boys;

Above 1.0, most of them are girls;

It is close to between 0.4 and 1.0, which is the critical value range, and it is possible for both men and women.

Then, the combined binomial values ​​(b-HCG and AFp) are more accurate:

The lower the MOM value of b-HCG (<0.4) and the higher the MOM value of AFp (>1), the more likely it is that the baby is a boy.

The higher the MOM value of b-HCG (>0.8) and the lower the MOM value of AFp (<1), the more likely it is that the baby is a girl.

In addition, in the blood cells of Down syndrome children and Down syndrome positive children, regardless of whether the fetus is a boy or a girl, the b-HCG value is higher, but the AFp value is slightly lower.

Is the Down syndrome screening result accurate in determining the gender of a child?

Down syndrome is a common chromosomal disease in humans. Because Down syndrome patients have severely low IQs and some cannot even be independent in their daily lives, almost all capitalist countries currently conduct Down syndrome screening on pregnant women in order to achieve the goal of eugenics. Therefore, Down screening is only a test for the risk of Down syndrome, and its results have nothing to do with the gender of the fetus. HCG is a test of the pregnant woman's blood cells, not a test of the fetus; AFP (alpha-fetoprotein) is a special protein produced by the fetal liver. Adults do not normally secrete this protein, so AFP is used as an indicator to consider whether the child's development is normal. Theoretically, these two indicators have no direct relationship with the baby's gender. After studying the records of more than 1,000 Down syndrome screening reports from the hospital, we found that these values ​​have little to do with the baby's gender. The opposite is true. Many AFP MOM values ​​are <1, but they are actually boys.

Editor's Tips:

There are only two genders in the human body: male and female. No matter which method is used to predict, the accuracy is 50%. This can lead to the illusion that some methods are very accurate. For a 100% accurate method, there is still only B-ultrasound. However, my country has completely banned the identification of fetal gender for non-medical purposes during pregnancy, so pregnant parents do not need to worry too much about the baby's gender. Why not relax and focus on preparing the baby's supplies and caring for the expectant mother's body in daily life.

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At 10 to 12 weeks of pregnancy, the baby's gender can be determined through advanced technical examinations. Popular methods include looking at the Qing Palace map and observing the abdomen, which are all topics of conversation after dinner and tea. The current scientific research methods for distinguishing gender are:

DNA blood test

A gene called "SRY" only exists on the Y chromosome. Once its presence is detected, it means that the fetus is male. This type of test can be performed 5 weeks after pregnancy, but my country does not have this service support.

B-ultrasound

In the B-ultrasound image, the male reproductive organ is shaped like a pot handle, while the female reproductive organ is shaped like a flower. Even experienced doctors can make mistakes in diagnosis. The accuracy of B-ultrasound diagnosis is only about 85% to 90%, and the test can usually be performed after the fetus is 4 months old. Ultrasound is a type of sound wave frequency. Reports to date have shown that it has no adverse effects on the fetus, so it is widely used in obstetrics and gynecology. When using ultrasound to diagnose the sex of a fetus, the accuracy for a boy is over 95%, while the reliability for a girl is only around 85%.

Amniocentesis

When the fetus is 15 weeks old, every 1 ml of amniotic fluid contains nearly 10,000 fetal cells. By taking the amniotic fluid cells of these pregnant women and analyzing their sex chromosomes, the gender of the baby can be determined. However, it is an invasive examination method with the potential for trauma. It is used to screen fetal health problems in older mothers and families with a large family history of genetic diseases. It has certain risks and may cause miscarriage and other situations in fetuses with inherent problems. Therefore, this test must be performed in a reliable hospital by an experienced doctor so that the doctor can resolve any subsequent problems. Therefore, it is neither recommended nor reasonable to use amniocentesis to test the sex of the fetus. The medical community does not approve of performing amniocentesis just to determine the sex of the fetus.

Villus needle biopsy (shaving)

The chromosome karyotype of the villus somatic cells was consistent with that of the test tube embryos. The accuracy of this method can reach over 90%. Although the use of chorionic villus aspiration biopsy can determine the sex of the fetus around 10 weeks of pregnancy, it may cause miscarriage (3% to 5%) and may also harm the fetus. This resulted in the mutilation of his hands and feet. Therefore, it is best not to undergo this type of test simply to determine the sex of the fetus.

Salt water cleaning of the uterus

It is one of the more effective methods of its kind in recent years and is usually performed at 9 weeks of pregnancy. So far, it has been confirmed that the safety factor is very high, with a reliability of 98%. However, this type of test can only detect males and females, and cannot know whether the fetus's sex chromosomes are normal. In addition, you can reduce the error by not having sex within a week before the test.