Why is there a fetal heartbeat when hcg doubles?

If Hcg doubling is not good, fetal heartbeat will appear. This is a symptom caused by successful implantation. It is a very critical link during early pregnancy. If the fetal heartbeat does not appear, the pregnancy will become quite unsmooth. It may be that the fetus has more serious problems. If it cannot be solved, it is necessary to prepare for termination of pregnancy in time to prevent greater impact on the uterus.

Related information

In a mature woman, the fertilized egg moves to the uterine cavity and implants to form an embryo. During the development and growth into a fetus, the placental syncytiotrophoblast cells produce a large amount of human chorionic gonadotropin (HCG), which can be excreted into the urine through the pregnant woman's blood circulation. During the 1st to 2.5th week of pregnancy, the HCG level in serum and urine will increase rapidly, reaching a peak in the 8th week of pregnancy, and then dropping to a moderate level in the 4th month of pregnancy, and remaining until the end of pregnancy.

Detection Methods

1. Latex aggregation inhibition test and hemagglutination inhibition test

2. Radioimmunoassay (RIA)

3. Enzyme-linked immunosorbent assay (ELISA)

4. Monoclonal antibody colloidal gold test

The examination of HCG is of great significance for the diagnosis of early pregnancy, and has certain value in the diagnosis, differentiation and course observation of pregnancy-related diseases, trophoblastic tumors and other diseases.

1. Diagnosis of early pregnancy: HCG can rise to greater than 2500 mIU/mL 35 to 50 days after pregnancy. It can reach 80,000 mIU/mL in 60 to 70 days. The urine HCG level in multiple pregnancies is often higher than that in single pregnancies.

2. Determination of abnormal pregnancy and placental function:

①

Ectopic pregnancy: In the case of ectopic pregnancy, this test has only a 60% positive rate. HCG may still be positive 3 days after uterine bleeding, so HCG examination can be used to differentiate it from other acute abdominal diseases. HCG is usually 312-625 mIU/mL.

②

Diagnosis and treatment of miscarriage: In case of incomplete miscarriage, if there is still placental tissue remaining in the uterus, the HCG test may still be positive. In case of complete miscarriage or stillbirth, the HCG test will turn from positive to negative, so it can be used as a reference for fetal preservation or aspiration treatment.

③

Threatened abortion: If HCG levels in urine remain high, unavoidable abortion will not occur. If the HCG level is below 2500 mIU/mL and gradually decreases, there is a possibility of miscarriage or stillbirth. When it drops to 600 mIU/mL, miscarriage is inevitable. During the treatment to preserve pregnancy, if HCG continues to decrease, it means that the pregnancy preservation is ineffective. If HCG continues to rise, it means that the pregnancy preservation is successful.

④

4 days after delivery or 13 days after artificial abortion, serum HCG should be lower than 1000 mIU/mL, and 9 days after delivery or 25 days after artificial abortion, serum HCG should return to normal. If this situation is not met, the possibility of abnormality should be considered.