Uterine atony

What is uterine inertia?

As labor progresses, uterine contractions gradually increase, contraction time becomes longer, intervals become shorter, and powerful uterine contractions encourage labor to continue. But some mothers-to-be contractions are not enhanced with the birth process, it is bound to prolong the labor process, this situation is called uterine atony, divided into primary and secondary two kinds.

In the course of childbirth, the abnormal rhythm, symmetry and polarity of uterine contraction or intensity and frequency change, called abnormal uterine contraction force. Obstructive dystocia is usually caused by abnormal birth canal or fetal factors, which increases fetal resistance through the birth canal and leads to secondary abnormal fertility.

The abnormal uterine contractility can be divided into two types: uterine atony and uterine hypertonia. Each type of abnormal uterine contraction can be divided into coordinated uterine contraction and inconsistent uterine contraction. Uterine atony refers to the polarity, symmetry and rhythm of contractions, but contractions are weak and weak, short duration, long or irregular intervals.

Uterine atony refers to the uterine contraction is still maintained normal rhythm, symmetry and polarity, but the contraction intensity is decreasing, resulting in prolonged contraction interval, shortened duration, each contraction when the strength is weak, slow expansion of the uterine mouth, prolonged delivery time, fetal threat, maternal fatigue. But the uterine orifice is delayed, resulting in delayed labor, resulting in fetal head into the pelvic, bladder is compressed between the fetal head and pubic symphysis, dysuria, urinary retention; affect the placenta from the uterine wall peeling, causing postpartum hemorrhage; increase the chance of fetal hypoxia and trauma.

If the puerpera is due to the tension and fear of childbirth caused by uterine inertia, the prospective father and family should be patient to ease up, and ultimately normal childbirth.

Causes and symptoms of uterine inertia


Causes of primary uterine atony. From the beginning, the contraction of uterine muscles is very weak, or uterine muscle edema and obstruction of contraction, multiple births, excessive amniotic fluid and other reasons can also cause uterine atony.

The cause of secondary uterine inertia. If the pelvic stenosis, fetal head position is not correct, resulting in normal delivery can not be carried out, maternal fatigue, contractions will become uncoordinated. In addition, maternal heart tension, pain, but also prolonged the duration of labor, resulting in uterine inertia.


Postpartum hemorrhage occurring before the placenta is delivered is called the third stage of labor hemorrhage. Placental bleeding before delivery may not be sudden massive bleeding, but more stable bleeding, such bleeding at any point in time is appropriate, but will continue until serious hypovolemia. However, special attention should be paid to the bleeding situation after the placenta is delivered. Because the uterus at the placenta peeling site needs to constrict the blood vessels and block the lumen to stop bleeding, when the uterus is weak, a large amount of blood will be lost immediately. If the hemostasis or blood transfusion is too slow, the patient will fall into a coma, uterine failure, will endanger maternal life.

Primary uterine atony refers to the onset of labor on the uterine atony, the mouth of the uterus can not expand as scheduled, fetal exposure can not decline as scheduled, resulting in prolonged labor; Secondary uterine atony refers to the labor process began uterine contraction normal, but in the late stage of labor (mostly in the late active stage or the second stage), uterine contraction weakened, labor. Progress is slow or even stagnant.

Treatment of uterine atony

1, exclude birth canal, fetal dystocia to formulate delivery mode.

2, we expect to enhance maternal physical strength and uterine contraction from vaginal delivery.

3. Have head pelvic disproportion, fetal distress, fetal abnormalities, placenta previa, uterus over-expansion, elderly lying-in women, uterus over-expansion with uterus and cervical surgery carefully.

4, prevention of postpartum hemorrhage and infection after improvement.

5. If the opening of uterine membranes is less than 3 cm wide, enema with warm soapy water should be done first, and then artificial rupture should be done after defecation.

6. Vitamin B1 acupoint injection and oxytocin intravenous drip can be used if the above treatment is ineffective or secondary uterine atony.

7. Those with mental stress and poor physical strength should be given rest.

8, eat less dehydration, as appropriate, fluid replacement.

General treatment: eliminate mental stress, rest and encourage more food. Those who can not eat can receive intravenous nutrition supplementation and add vitamin C 2G to Deng 10% glucose solution 500 to 1000ml. 5% sodium bicarbonate should be supplemented with acidosis. Potassium hypochloremia should be given slow infusion of potassium chloride. Maternal excessive fatigue, can give diazepam 10 mg slow intravenous injection or dolantin 100 mg intramuscular injection, after a period of time, can make the uterine contraction strength. For primipara with cervical enlargement less than 3 cm and unbroken membranes, warm soap water enema should be given to promote intestinal peristalsis, expel feces and gas, and stimulate uterine contraction. If it is difficult to urinate naturally, induction should be done first, and catheterization should be given when it is ineffective, because emptying the bladder can widen the birth canal and promote uterine contraction.

How to prevent uterine inertia

1, do good health care during pregnancy. According to antenatal examination and identification, the delivery mode (vaginal delivery or cesarean section) can be arranged preliminarily. If the fetal position is not correct, it can be corrected as early as possible.

2, correct understanding of childbirth. Understand the delivery process, overcome fear and mental tension, and the brain can correctly control uterine contraction.

3, we should arrange daily life in the delivery process. After birth, they must eat, drink, stool and sleep on time. When uterine contraction is physically exhausting, we should replenish energy in time. Only in this way can we be competent for the heavy physical labor of childbirth.

4, maternal production process should actively cooperate with production. During the labor process, the parturient should cooperate closely with the medical staff. It is beneficial and harmless to do so according to the requirements of the medical staff. Medical staff should closely observe and correctly handle the labor process, each step and operation should be careful, careful, everything for the health of mother and baby.

Because of uterine inertia, prolonged labor has adverse effects on both the mother and the child. Once uterine atony occurs, the doctor should make a comprehensive analysis of the three major factors of labor, birth canal and fetus, and according to the maternal in different stages of labor to do different treatment.

We should check the birth canal and fetal position when there is uterine inertia. If obstruction of the birth canal or improper estimation of the fetal position can not be delivered through Yin, cesarean section should be carried out in time; if it can be estimated that vaginal delivery, should try to strengthen uterine contraction, such as the elimination of maternal tension; if the maternal extreme fatigue, can be given sedatives, so that the maternal full rest, while paying attention to supplementary nutrition; if the maternal can not eat food If the uterine contraction is still not improved, it is feasible to break the membrane artificially. After breaking the membrane, the fetal head is close to the lower uterine segment and the cervix, which causes the uterine contraction reflexively. Uterine contraction can also be enhanced by intravenous drip of oxytocin.