Reasons for high hcg values ​​in Down syndrome screening

Female friends will be asked to do a Down syndrome screening hCG test when they are 4 months pregnant. The reference range of the median multiple of β-hCG is 0-2.5. If it is higher than this value, you should pay special attention. If it is caused by physiological reasons, such as misremembering the last menstrual cycle, multiple pregnancy, etc., there is no need to worry in these two cases, but it may also be caused by hydatidiform mole, gestational hypertension, etc., which is extremely detrimental to the healthy growth of the fetus.

1. Reasons for high hcg values

1. The time of the last menstrual period may be miscalculated, resulting in a discrepancy between the actual gestational age and the estimated gestational age.

2. It may be twins or multiple births, because the value of multiple pregnancy is higher than that of single pregnancy.

If the doctor confirms that it is one of the above two situations, then the pregnant woman does not need to worry.

3. It may be an abnormal pregnancy - hydatidiform mole. The blood hCG value is usually higher than the normal pregnancy value of the corresponding gestational week. If a hydatidiform mole is confirmed, the patient needs to be hospitalized immediately.

4. On the Down syndrome screening checklist, the reference range of the median multiple of β-hCG is 0-2.5. If it is higher than this value, it will have an adverse effect on the safety of mother and child during pregnancy. For example, pregnant women are more likely to suffer from gestational hypertension. This needs to be judged based on the actual individual situation. Some pregnant women have received hCG injections to preserve the fetus in early pregnancy, so there is a possibility that the hCG values ​​will be high during the Down syndrome screening.

2. What is the normal reference value of hcg for Down syndrome screening?

HCG (human chorionic gonadotropin) is the "pregnancy test" hormone that is familiar and most commonly used by obstetricians and gynecologists. It is composed of α and β dimers of glycoprotein. But the α-subunit is common to all anterior pituitary hormones. The β-subunit is specific to HCG. The complete HCG is produced entirely by the syncytiotrophoblast of the placental chorion. Its main function is to stimulate the corpus luteum, which is beneficial to the continuous secretion of estrogen and progesterone, so as to promote the formation of uterine decidua and make the placenta grow and mature. It is now believed that HCG is produced by trophoblast transitional cells and syncytial cells. It increases rapidly during the first 8 weeks of pregnancy to maintain the pregnancy. After about 8 weeks of pregnancy, HCG gradually decreases until it reaches a relative stability around 20 weeks.

Ultrasound in the early stages of pregnancy cannot determine whether you are pregnant, but now blood HCG can be used to confirm it. Blood HCG is not only highly sensitive, but also can be used for accurate judgment because it is "quantitative" data.

Normal reference value of HCG: The normal value of blood HCG is <10μg/L, and the normal value of β-HCG is <3.1μg/L. The absolute values ​​of serum HCG vary greatly at different stages of pregnancy and between pregnant women, that is, they are different from person to person and are not comparable, and can only be compared within themselves. Generally, non-pregnant women’s blood HCG is <100IU/L. During the first 3 months of pregnancy, HCG levels approximately double every 2.2±0.5 days.