Uterine contraction is an abnormal productivity. According to the time of occurrence, it can be divided into primary uterine atony (appears at the beginning of labor) and secondary uterine atony (the uterus opens 3cm into the active period). Twins, excessive amniotic fluid, and large uterus tension Poor elasticity, loss of normal contractions, or loss of normal polarity and symmetry of the uterine malformation, causing uncoordinated contractions.
Although the performance of uterine contraction is local, but the cause is caused by a combination of various factors, common ones are:
(1) Mental factors, especially primipara, fear of childbirth, excessive tension, disrupting the normal function of the central nervous system and causing fatigue.
(2) Uterine factors: twins, excessive amniotic fluid, large children make the uterus tension, poor elasticity, loss of normal contractions, or the loss of normal polarity and symmetry of the uterine malformation, causing uncoordinated contractions.
(3) The head basin is not called, the fetal position is abnormal, and the first exposure of the tire can not be close to the cervix and neck, and can not cause effective reflex contractions.
(4) bladder and rectal filling, often affecting uterine contractions.
(5) Endocrine abnormalities, the main hormones involved in the delivery process at the end of pregnancy: the secretion and function of estrogen, progesterone, oxytocin, prostaglandins, acetylcholine, etc., affect the uterine muscle excitability.
(6) Improper treatment of labor: excessive use of sedatives too early, meperidine, magnesium sulfate, etc. can cause uterine contraction, or less maternal feeding, improper rest and care.
Examination of fetal heart height, fetal heart rate, fetal uterus size, fetal heart rate monitoring
1. If the pelvic stenosis of the mother or the head of the fetus is too large, the birth can not pass through the birth canal; or the pelvis is normal, but because the head of the fetus is too large, it can not pass the birth canal uterus contraction weak and weak, long labor.
2. Primary uterine weakness, refers to the anterior half of the pelvic entrance plane is narrow, not suitable for the connection of the fetal head occipital, the uterus contraction is weak at the beginning of the wider half of the lower part of labor.
3. Secondary uterine atony, which means that the uterine contraction is weak when the labor progresses to a certain stage.
4. The intrauterine pressure is less than 4KPa. Common fetal position abnormalities or head basin disproportionate; followed by uterine dysplasia and mental factors.
Abnormal fetal position: abnormal fetal position generally refers to the position of the fetus in the uterus after 30 weeks of pregnancy, and longer in pregnant women and women who have loose abdominal wall. Abnormal fetal position includes breech position, transverse position, posterior occipital position, and facial position. More common in the breech position, and the horizontal position harms the mother and baby. Because abnormal fetal position will bring different degrees of difficulty and danger to childbirth, early correction of fetal position is of great significance for the prevention of dystocia.
Developmental pelvic abnormalities: the anterior half of the pelvic entrance plane is narrow, not suitable for the connection of the fetal head occipital, the latter half is wider, and the fetal head is easy to connect with the posterior or occipital position.
The uterus is a horizontal ellipse: the position of the abnormal fetal position in the uterus is called the fetal position. The transverse ellipse of the uterus is one of the basis for diagnosing the transverse position of the fetus. The transverse position is a kind of abnormal fetal position, and the other includes breech position, lateral position, posterior position, and facial position. More common in the breech position, and the horizontal position harms the mother and baby.
The head basin is not called: if the maternal pelvis is narrow or the head of the fetus is too large, it cannot pass through the birth canal during childbirth; or the pelvis is normal, but because the head of the fetus is too large, it cannot pass through the birth canal. This phenomenon is called the head basin. Not called."