Does hcg not double? Does it mean that the fetus has stopped growing?

HCG can not only confirm pregnancy, but also judge whether the pregnancy development is normal according to the level of HCG increase. Generally, the HCG doubling test needs to be carried out at intervals of days during early pregnancy, that is, the HCG level is tested twice at an interval of one day. If the level of the second test is about twice that of the first, it is called doubling, indicating that the embryonic development is normal.

Human chorionic gonadotropin is a glycoprotein metabolized by the trophoblast cells of the embryo and is composed of α and β dimers of glycoprotein. Human chorionic gonadotropin (HCG) αβ, produced by trophoblasts.

The glycoprotein growth hormone with a content of 36700, the α subunit is basically similar to the FSH (follicle-stimulating hormone), LH (luteinizing hormone) and TSH (thyroid-stimulating hormone) metabolized by the pituitary gland, so they can produce cross-reactions with each other, while the structure of the β subunit is different. β-HCG has a similar structure to β-LH, but some of the last 24 carbohydrates are not present in β-LH.

effect.

(1) It has the functions of FSH and LH, maintains the service life of menstrual progesterone, and expands menstrual progesterone into pregnancy progesterone;

(2) Promote the aromatization of androgen into estrogen and stimulate the production of progesterone;

(3) Inhibit the stimulating effect of plant lectins on reticulocytes. Human chorionic gonadotropin can be adsorbed on the surface of trophoblast cells to prevent the trophoblast cells of test tube embryos from being attacked by the reticulocytes of pregnant mothers;

(4) LH-like effect: before the fetal pituitary gland secretes LH, it stimulates the fetal testicles to secrete testosterone to promote male sexual division; it can also promote the development of sex hormones, 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 pituitary synergism. It can not only promote the growth of sex hormones and the secretion of androgens, but also promote the development of secondary sexual characteristics.

(5) It can fuse with the TSH protein kinase of the somatic cells of the pregnant mother's thyroid cyst and stimulate the specificity of thyroid cyst.

. Expand and write this section to change the concentration value.

Human chorionic gonadotropin enters the maternal blood after fertilization and increases rapidly until the 8th week of pregnancy, then slowly decreases in concentration until the 18th to 20th week, and then remains there for a long time. Generally, a level of at least 2.5 MoM of human chorionic gonadotropin is associated with Down syndrome. However, the actual human chorionic gonadotropin level in the maternal blood of DS patients is only 1.3 MoM on average, which cannot significantly distinguish DS patients. The human chorionic gonadotropin related molecules used for DS testing include mineral acid b-hCG and glucose hCG (H-hCG).

The level of human chorionic gonadotropin-related molecular structures is also related to the identification of fetal sex. The level of human chorionic gonadotropin in baby girls is significantly higher than that in baby boys.

All human chorionic gonadotropin is produced by the transformed trophoblast of the embryonic chorion. Human chorionic gonadotropin is produced by a combination of trophoblastic transitional somatic cells and germ cells. Human chorionic gonadotropin begins to be metabolized 10-14 days after pregnancy.