What is the hcg injection

Physical health is very important during pregnancy. Pregnant women should go to the hospital regularly for physical check-ups. This is to promote physical health and to see the development of the baby in the belly. However, during the examination, the doctor will always tell them about the hcg injection. In fact, this is related to the physical condition. So what is the hcg injection?

Human chorionic gonadotropin is a glycoprotein secreted by trophoblast cells of the placenta and is composed of α and β dimers. Human chorionic gonadotropin (HCG) αβ is synthesized by syncytial trophoblasts.

A glycoprotein hormone with a molecular weight of 36,700. The α subunit is basically similar to FSH (follicle stimulating hormone), LH (luteinizing hormone) and TSH (thyroid stimulating hormone) secreted by the pituitary gland, so they can cross-react with each other, while the structures of the β subunits are different. β-HCG is similar to β-LH in structure, but the last 24 amino acids are not present in β-LH.

Function

(1) It has the functions of FSH and LH, maintaining the life of the menstrual corpus luteum and making it enlarge into the corpus luteum of pregnancy;

(2) Promote the aromatization of androgens into estrogens and stimulate the formation of progesterone;

(3) Inhibit the stimulation of lymphocytes by plant lectins. Human chorionic gonadotropin can be adsorbed on the surface of trophoblast cells to prevent embryonic trophoblast cells from being attacked by maternal lymphocytes;

(4) LH-like function: before the fetal pituitary gland secretes LH, it stimulates the fetal testicles to secrete testosterone to promote male sexual differentiation; it can also promote gonadal development, and in men, it can stimulate the activity of interstitial cells in the testicles and increase the secretion of androgen (testosterone). It is of great significance for the treatment of male patients with combined pituitary deficiency. It can not only promote gonadal development and the secretion of male hormones, but also promote the development of secondary sexual characteristics.

(5) Can bind to the TSH receptors of maternal thyroid cells and stimulate thyroid activity.

Fold edit this section concentration changes

Human chorionic gonadotropin enters the maternal blood after fertilization and proliferates rapidly until the 8th week of pregnancy, then slowly decreases in concentration until the 18th to 20th week, and then remains stable. Generally, an increase in the level of human chorionic gonadotropin to at least 2.5MoM is associated with Down syndrome. However, the actual average level of complete human chorionic gonadotropin in the maternal blood of DS patients is only 1.3MoM, which cannot clearly identify DS patients. The human chorionic gonadotropin-related molecules used for DS examination are free b-hCG and high sugar hCG (H-hCG).

The levels of human chorionic gonadotropin-related molecules are also related to the sex of the fetus. The levels of human chorionic gonadotropin in baby girls are significantly higher than those in baby boys.

Complete human chorionic gonadotropin is produced entirely by the syncytiotrophoblast of the placental chorion. Human chorionic gonadotropin is produced by trophoblast transitional cells and syncytial cells. Human chorionic gonadotropin begins to be secreted 10-14 days after conception.