Maternal factors Generally, pregnant women suffer from uterine malformations, such as congenital hypoplasia of double horn uterus, single horn uterus, double uterus and uterus mediastinum, which is easy to make the fetus premature, because the uterus is the place where the fetus grows. If the muscles of the uterus can't be stretched well, it is easy to have premature delivery. Congenital cervical dysplasia, or acquired cervical injury caused by childbirth, abortion or surgical operation, relaxation of the internal opening of the cervix, and swelling of the amniotic sac to the cervical canal can all lead to premature rupture of membranes and premature delivery. Sometimes, even if the uterus develops normally, it may be due to the excessive expansion of the uterus during pregnancy, such as multiple pregnancy and polyhydramnios, which leads to high intrauterine pressure and excessive stretching of uterine muscles, which is also a common cause of premature delivery. There are also intrauterine infections such as chorioamnionitis and premature rupture of membranes, which may lead to premature delivery. Fetuses living in poor placental function and poor uterine environment are prone to intrauterine growth retardation and intrauterine hypoxia, which has a worse prognosis than premature infants caused by other reasons.

Hyperdilatation of uterus

In twin or multiple pregnancies, amniotic fluid can increase intrauterine pressure and premature delivery occurs early.

Cervical incompetence

Anatomically, the neck has no real sphincter-like arrangement. Connective tissue is mainly composed of collagen fibers, which are elastic and have a sphincter-like effect on pregnant cervix. In the second trimester of pregnancy, when the isthmus of the uterus stretches to form the lower part of the uterus, the internal opening of the cervix relaxes, the internal pressure of the amniotic cavity gradually increases, the cervical opening passively expands, the amniotic sac bulges out of the cervical canal, and the membranes rupture due to tension changes or infection factors, leading to premature rupture of the membranes.

Bad living habits

Such as smoking, drug abuse, alcoholism and severe malnutrition.

other

Such as long-distance travel, climate change, plateau life, family migration, emotional fluctuation and other physical and mental burdens, direct abdominal impact, trauma, or surgery.

Pregnancy complications during pregnancy, if the mother suffers from acute infectious diseases, such as rubella, influenza, acute infectious hepatitis, acute pyelonephritis, acute cholecystitis, acute appendicitis, pregnancy-induced hypertension, heart disease, etc. These diseases can also easily lead to premature delivery. In addition, the mother's endocrine disorders, such as progesterone or estrogen deficiency, severe hyperthyroidism, diabetes and so on. ; Pregnant women with a history of trauma and surgery may be nervous and have high blood pressure, resulting in tissue hypoxia and insufficient oxygen supply to the uterus and placenta. Malnutrition and severe anemia of pregnant women, especially protein deficiency and vitamin E and folic acid deficiency; Abnormal placenta, too thick, too short and twisted umbilical cord are all causes of premature delivery.

Combined with acute or chronic diseases

Such as viral hepatitis, acute nephritis or pyelonephritis, acute appendicitis, viral pneumonia, high fever, rubella and other acute diseases, heart disease, diabetes, severe anemia, hyperthyroidism, hypertension, asymptomatic bacteriuria and other chronic diseases.

Combined with uterine malformation

Such as double horn uterus, mediastinal uterus, cervical relaxation, hysteromyoma, etc.

Pregnancy complications

Pregnancy with chronic nephritis, pregnancy with heart disease, pregnancy with hepatitis, pregnancy with lupus erythematosus, etc. On the one hand, due to medical complications, it can cause maternal systemic ischemia and hypoxia and insufficient placental perfusion, which is easy to induce premature delivery; On the other hand, the severity of the disease brings danger to the mother and causes iatrogenic premature delivery for the safety of the mother.

Pregnancy complications: placenta previa, placental abruption, pregnancy-induced hypertension syndrome, intrahepatic cholestasis of pregnancy.

Fetal factors twins, fetal malformation. Placenta previa and placental abruption. Too much or too little amniotic fluid, multiple pregnancy. Fetal intrauterine death, abnormal fetal position. Premature rupture of membranes and chorioamnionitis are also factors that are prone to premature delivery.

Social factors Premature labor easily occurs in people with low social level, no occupation and low economic income. This is because these people are engaged in excessive physical labor, working too long, overworked, unable to carry out normal prenatal examination, and have poor nutritional status. Premature delivery is also easy to happen to modern urban mothers, who have greater psychological pressure and work pressure, frequent emotional fluctuations and excessive mental stress; Some mothers are underweight in order to lose weight, which also easily leads to premature delivery of the fetus; There are also some pregnant women who ask for caesarean section in advance because of work reasons or fear of labor pains.

Environmental factors, environmental pollution and noise will also increase the risk of premature delivery.

Psychological factors Many scholars have found that psychological stress is directly related to premature delivery, such as family discord, aversion to children and poor economic conditions, which can seriously affect the mood of pregnant women, and its mechanism may be related to the release of prostaglandin from membranes and placentas mediated by ACTH.

Genetic factors, previous premature birth history and future premature birth are obviously related. Christensen's analysis of 1995 Danish women 13967 pregnancies is almost consistent with this. Women with a history of premature delivery not only have the risk of premature delivery recurrence, but also pass this risk on to their children. Wang (1995) and Poller( 1996) found that premature delivery has family aggregation and ethnic differences. Under the same social and economic conditions, the premature birth rate of blacks is 50%%u% higher than that of whites, so it is considered that premature birth is related to heredity.

Other factors: the premature delivery rate of pregnant women under 20 years old or over 35 years old is obviously higher, especially those under 20 years old and short stature, and the risk of premature delivery is higher. Those who have had a history of abortion in the past, especially late abortion, repeated abortion, induced abortion, induced labor or pregnancy less than one year after abortion, are most likely to be premature. Because abortion has different degrees of damage to the cervix, it will lead to cervical incompetence and increase the rate of premature delivery. Pregnant women have bad personal habits, such as smoking, drinking, partial eclipse, frequent and intense sexual life in the third trimester, which are easy to cause premature rupture of membranes, which is also a common cause of premature delivery.

Health Tips Pregnant mothers should pay attention to the fact that when there are regular contractions of at least 10 minutes from the 28th week to the 37th week of pregnancy, accompanied by shortened cervical canal, it can be diagnosed as threatened premature delivery. Regular uterine contractions (not less than 4 times in 20 minutes and lasting not less than 30 seconds), accompanied by cervical shortening of not less than 75% and cervical dilatation of more than 2cm, were diagnosed as premature delivery.

In this case, you need to go to the nearest local hospital as soon as possible.