Why does miscarriage happen?

Why does miscarriage happen? Friends who have experienced such a thing will have this question. Abortion is divided into artificial abortion and natural abortion. Artificial abortion is a human act because you don't want to keep the baby, so I won't say much about it. The following will introduce why natural abortion occurs. This question confuses friends who want to keep the baby, and they will also feel regretful and sad.

There are many reasons for spontaneous abortion, some of which can be very complicated. It may be a potential disease in the body, or a genetic problem, or the pregnant woman may be in poor physical condition, etc. Some pregnant women can go to work normally after pregnancy. Excessive fatigue and lack of rest may also lead to miscarriage. Therefore, pregnant women must take good care of themselves. Only when they are well can they provide a healthy growth environment for their babies.

Causes

1. Genetic defects

In early spontaneous abortion, 50% to 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, which 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

(1) 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.

(2) Reproductive organ diseases Pregnant women may have uterine malformations (such as double uterus, septate uterus and uterine hypoplasia) and pelvic tumors (such as uterine fibroids), which may affect the growth and development of the fetus and lead to miscarriage. If the internal os of the cervix is ​​loose or the cervix is ​​severely lacerated, late miscarriage may occur easily due to premature rupture of membranes.

(3) Endocrine disorders such as hypothyroidism, uncontrolled severe diabetes, and luteal insufficiency can all lead to miscarriage.

(4) Traumatic abdominal surgery during pregnancy, especially in the early stages of pregnancy, or trauma during mid-pregnancy can cause uterine contractions and lead to miscarriage.

4. Insufficient placental endocrine function

In early pregnancy, the corpus luteum of the ovary secretes progesterone, and 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.

Now we have a basic understanding of why miscarriage occurs. If you always have miscarriages, it will easily become habitual miscarriage and lead to infertility. Therefore, if miscarriage occurs, you must take it seriously. After all, it is not easy to conceive a new life. I hope all pregnant women are healthy.