What is related to miscarriage? 8 factors that lead to miscarriage

Any pregnancy that ends before 28 weeks is called miscarriage. If it occurs before 12 weeks of pregnancy, it is called early miscarriage, which is more common; if it occurs between 12 weeks and less than 28 weeks of pregnancy, it is called late miscarriage.

There are many reasons for miscarriage, the main ones are:

① Genetic defects: Most embryos with abnormal chromosome number or structure cannot continue to develop and are aborted early.

② Adverse external factors: Chemical substances (such as cadmium, lead, organic mercury, DDT and tobacco) and physical factors (such as radioactive substances, noise and high temperature) can directly or indirectly cause damage to the embryo or fetus and lead to miscarriage.

③Maternal systemic diseases. Acute illness during pregnancy and high fever can cause uterine contractions; bacterial toxins or viruses entering the fetal blood circulation through the placenta can cause fetal death and lead to miscarriage. Pregnant women with severe anemia or heart failure can cause fetal hypoxia; chronic nephritis or hypertension can cause placental infarction and also cause miscarriage.

④ Maternal reproductive organ diseases. Uterine malformations (such as bicornuate uterus, septate uterus, etc.), uterine hypoplasia, pelvic tumors (such as uterine fibroids, etc.) can affect the growth and development of the fetus and lead to miscarriage. Relaxation or deep lacerations of the internal cervical os can easily cause rupture of the fetal membranes and cause late miscarriage.

⑤ Maternal endocrine dysfunction. Insufficient corpus luteum function of the ovary leads to less secretion of progesterone, which affects the formation of uterine decidua and placenta; hypothyroidism and less secretion of thyroid hormone affect embryonic development and can cause miscarriage.

⑥ Maternal trauma. Abdominal surgery during pregnancy, especially in the early stages of pregnancy, or trauma during mid-pregnancy can stimulate uterine contractions and cause miscarriage.

⑦ Insufficient placental endocrine function. After 8 weeks of pregnancy, the placenta gradually becomes the main place for the production of progesterone. In addition, the placenta also synthesizes chorionic gonadotropin, placental lactogen, estrogen, etc. In the early pregnancy, if the amount of the above hormones is insufficient, the pregnancy will be difficult to continue and miscarriage will occur.

⑧Immune factors. Pregnancy is like a transplant of the same species. There is a complex and special immunological relationship between the embryo, fetus and mother, so that the embryo and fetus are not rejected. If the mother and fetus are not immune-compatible, it may cause the mother to reject the fetus and cause miscarriage.

Depending on the course of development, miscarriage can be divided into the following types:

1. Threatened miscarriage

Refers to a small amount of vaginal bleeding or (and) lower abdominal pain before 28 weeks of pregnancy, the cervix is ​​not open, the membranes are not broken, there is only a sign of miscarriage, but there is still hope for the pregnancy to continue. At this time, you should rest in bed and avoid sexual intercourse; oral sedatives, such as 0.03 grams of phenobarbital, 3 times a day. Progesterone 20 mg, injected intramuscularly once a day, has a fetal preservation effect for those with corpus luteum insufficiency. Low-dose thyroxine tablets are suitable for those with hypothyroidism. In addition, vitamin E has a similar effect to progesterone and can also be used. After two weeks of treatment, if the symptoms do not improve or even worsen, it is advisable to terminate the pregnancy.

2. Miscarriage is inevitable

It means that miscarriage is inevitable. It usually develops from threatened miscarriage. At this time, vaginal bleeding increases and paroxysmal abdominal pain intensifies. During the examination, the cervix has dilated, and sometimes tissue can be seen blocking the cervix. The size of the uterus is consistent with the month of menopause or slightly smaller. If miscarriage is inevitable in the late stage, the fetal membrane sac can be seen protruding from the cervix or amniotic fluid can be seen flowing out. The products of pregnancy should be completely expelled as soon as possible. Early miscarriage should be immediately treated with curettage; late miscarriage can be induced with oxytocin.

3. Incomplete abortion

It means that the products of conception have been partially discharged, but some of them are still left in the uterine cavity, which is the result of inevitable miscarriage. Because some products of conception remain in the uterine cavity, the uterine contraction is affected, resulting in continuous bleeding, and even heavy bleeding and shock. During the examination, blood continues to flow out from the dilated cervical opening, and sometimes placental tissue can be seen blocking the cervical opening, and the uterus is smaller than the month of amenorrhea. Vacuum extraction or curettage should be performed immediately to remove the residual tissue in the uterine cavity. For those with longer bleeding time, antibiotics are needed to prevent and treat infection. For those with heavy blood loss, timely infusion and blood transfusion are required.

4. Complete miscarriage

It means that all the products of pregnancy have been expelled, vaginal bleeding has gradually decreased, and abdominal pain has also disappeared. During the examination, the cervix is ​​closed and the uterus is shrunk. Generally, no special treatment is required.

5. Missed abortion

Refers to the embryo or fetus that has died in the uterus but has not been expelled naturally. Most pregnant women have had signs of miscarriage. Later, the uterus no longer grows but shrinks, the early pregnancy reaction disappears, and sometimes the vagina bleeds repeatedly, the amount is more or less, and it is dark brown. If it is already the second trimester, the pregnant woman does not feel the abdomen enlargement, and the original fetal movement disappears. During the examination, the cervix is ​​closed and the uterus is smaller than the month of amenorrhea. After the diagnosis is confirmed, it should be treated in time, because if the retention time is too long, the coagulation mechanism may be impaired, causing severe bleeding.

6. Habitual miscarriage

Refers to those who have had spontaneous abortions three or more times in a row. Each abortion often occurs in the same month of pregnancy. The causes of early habitual abortion are often luteal insufficiency, hypothyroidism, chromosomal abnormalities, etc. The most common causes of late habitual abortion are relaxation of the internal cervical os, uterine malformations, uterine fibroids, etc. Women with a history of habitual abortion should undergo necessary examinations before getting pregnant again, including examinations of reproductive organs (whether there are uterine malformations, uterine cavity adhesions, relaxation of the internal cervical os or uterine fibroids, etc.) and ovarian function. In addition, chromosome examinations and blood type identifications of both husband and wife are required, as well as semen examinations of the husband. If the cause is found and can be corrected, it should be treated before pregnancy. When the cause is unknown, the basal body temperature should be measured. Once the basal body temperature continues to rise for 3 weeks in the late menstrual cycle without falling, it indicates the possibility of pregnancy, and measures to preserve the fetus should be taken. The main thing is to avoid fatigue, rest in bed, abstain from sexual intercourse, and under the guidance of a doctor, use drugs such as chorionic gonadotropin, progesterone, thyroxine, vitamin E, etc. as appropriate until the gestational weeks exceed the period when miscarriage occurred in the past.