Is threatened miscarriage serious?

The harm of threatened abortion is quite large, and it can easily lead to miscarriage of the fetus, which is also quite harmful to women's physical health. When women have gynecological diseases, genetic defects, or systemic diseases, they are prone to threatened abortion. In order to prevent threatened abortion, it is necessary to strengthen prenatal checkups after pregnancy and do a good job of daily conditioning and health care.

1. Genetic defects: In early spontaneous abortions, 50%-60% of embryos have chromosomal abnormalities, most of which are abnormalities in chromosome number, followed by abnormalities in chromosome structure. Numerical abnormalities include trisomy, triploidy and X-monosomy; structural abnormalities include chromosome breakage, inversion, deletion and translocation. Most embryos with chromosomal abnormalities end in miscarriage. A very small number may continue to develop into a fetus, but some functional abnormalities or combined malformations may occur after birth. If a miscarriage has occurred, the products of conception are sometimes just an empty gestational sac or a degenerated embryo.

2. Environmental factors: There are many adverse external factors that affect reproductive function and can directly or indirectly cause damage to the embryo or fetus. Excessive exposure to certain harmful chemicals (such as arsenic, lead, benzene, formaldehyde, chloroprene, ethylene oxide, etc.) and physical factors (such as radiation, noise and high temperature, etc.) can cause miscarriage.

3. Maternal factors: Systemic diseases: Acute illness during pregnancy and high fever can cause uterine contractions and lead to miscarriage; bacterial toxins or viruses (herpes simplex virus, cytomegalovirus, etc.) enter the fetal blood circulation through the placenta, causing fetal death and miscarriage. In addition, pregnant women suffering from severe anemia or heart failure may cause fetal hypoxia and may also cause miscarriage. If a pregnant woman suffers from chronic nephritis or hypertension, the placenta may become infarcted and cause miscarriage.

4. Insufficient placental endocrine function: In the early stages of pregnancy, in addition to the secretion of progesterone by the corpus luteum of the ovary, the placental trophoblast cells also gradually produce progesterone. After 8 weeks of pregnancy, the placenta gradually becomes the main site for the production of progesterone. In addition to progesterone, the placenta also synthesizes other hormones such as β-chorionic gonadotropin, placental lactogen and estrogen. During early pregnancy, the above hormone levels drop, making it difficult for the pregnancy to continue and leading to miscarriage.

5. Immune factors: Pregnancy is like allogeneic transplantation. There is a complex and special immunological relationship between the embryo and the mother, which prevents the embryo from being rejected. If the immune system of both mother and child is not compatible, the mother may reject the embryo and cause miscarriage. The relevant immune factors mainly include paternal tissue compatibility antigens, fetal specific antigens, blood type antigens, maternal cellular immune disorder, insufficient maternal blocking antibodies during pregnancy, and insufficient maternal cytotoxic antibodies against paternal lymphocytes.