What to do when uterine contractions are weak

Uterine atony is a common disease among female friends. I believe many female friends have suffered from this problem. So how can we resolve this problem? What causes uterine atony? What should we do when uterine contractions are weak? The following points introduce us to what we should do when the uterus contracts weakly. Let’s take a look together.

Whether coordinated uterine atony is primary or secondary, once coordinated uterine atony occurs, the cause should be sought first, including whether there is cephalopelvic disproportion and abnormal fetal position, and the condition of cervical dilatation and descent of the fetal presenting part. If cephalopelvic disproportion is found and vaginal delivery is estimated to be impossible, cesarean section should be performed promptly. If there is no cephalopelvic disproportion and abnormal fetal position and vaginal delivery is estimated to be possible, measures to strengthen uterine contractions should be considered.

General treatment: eliminate mental stress, get more rest, and encourage eating more. Those who cannot eat can receive intravenous nutrition supplements by giving 500-1000ml of 10% glucose solution plus 2g of vitamin C. If accompanied by acidosis, 5% sodium bicarbonate should be supplemented. In case of hypokalemia, potassium chloride should be given by slow intravenous drip. If the mother is overly tired, she can be given 10 mg of diazepam slowly injected intravenously or 100 mg of pethidine injected intramuscularly. After a period of time, the uterine contraction force can be strengthened. For primiparas whose cervix is ​​less than 3 cm dilated and whose fetal membranes have not ruptured, they should be given warm soapy water enema to promote intestinal peristalsis, expel feces and gas, and stimulate uterine contraction. For those who have difficulty urinating naturally, the induced method should be tried first. If it is ineffective, catheterization should be performed because emptying the bladder can widen the birth canal and promote uterine contraction.

2) Strengthen uterine contraction: After general treatment, if the uterine contraction is still weak, it is diagnosed as coordinated uterine atony, and there is no obvious progress in the labor process. The following methods can be used to strengthen uterine contraction:

① Artificial rupture of membranes: Artificial rupture of membranes can be performed if the cervix is ​​dilated 3cm or more, there is no cephalopelvic disproportion, and the fetal head is engaged. After rupture of membranes, the fetal head is directly against the lower uterine segment and cervix, causing reflex uterine contractions and accelerating the progress of labor. Current scholars advocate that artificial rupture of membranes can be performed for those with unengaged fetal heads, believing that rupture of membranes can promote the descent of the fetal head into the pelvis. When rupturing membranes, it is necessary to check whether the umbilical cord is exposed, and rupture of membranes should be performed during the interval between uterine contractions. After rupturing the membranes, the surgeon's finger should remain in the vagina. After 1 to 2 uterine contractions and when the fetal head enters the pelvis, the surgeon can remove the finger. Bishop proposed using the cervical maturity scoring method to estimate the effectiveness of measures to enhance uterine contractions, see Table 1. If the maternal score is 3 points or below and artificial rupture of membranes has failed, other methods should be used. The success rate for scores of 4 to 6 is about 50%, the success rate for scores of 7 to 9 is about 80%, and all scores above 9 are successful.

Table 1 Bishop cervical maturity scoring method

Index score

0 1 2 3

Cervical dilation (cm) 0 1～2 3～4 5～6

Endocervical canal regression (%) (non-regression is 2 cm) 0-30 40-50 60-70 80-100

Presenting position (ischial spine level = 0) -3 -2 -1～0 +1～+2

Cervical hardness Hard Medium Soft

Cervical position: Posterior Middle Anterior

② Intravenous injection of valium: Valium can relax the cervical smooth muscle, soften the cervix and promote cervical dilation. Suitable for slow cervical dilation and cervical edema. The commonly used dose is 10 mg intravenous push, which can be repeated at intervals of 2 to 6 hours. The effect is better when used in combination with oxytocin.

③ Intravenous infusion of oxytocin: Suitable for patients with weak coordinated uterine contractions, good fetal heart rate, normal fetal position, and cephalopelvic proportion. Add 2.5U of oxytocin into 500ml of 5% glucose solution so that each drop of glucose solution contains 0.33mU of oxytocin. Start with 8 drops/min, i.e. 2.5mU/min, and adjust according to the strength of uterine contractions, usually not exceeding 10mU/min (30 drops/min). Maintain the intrauterine pressure at 6.7-8.0kPa (50-60mmHg) during contractions. The contractions are spaced 2-3 minutes apart and last 40-60 seconds. For those who are insensitive, the dose of oxytocin can be increased.

During the intravenous infusion of oxytocin, a dedicated person should observe uterine contractions, listen to the fetal heart rate and measure blood pressure. If uterine contractions last for more than 1 minute or the fetal heart rate changes, the infusion should be stopped immediately. The half-life of oxytocin in maternal blood is 2 to 3 minutes. The condition will improve rapidly after discontinuation of the drug. If necessary, sedatives can be added to inhibit its effect. If blood pressure is found to be high, the infusion rate should be slowed down. Because oxytocin has an antidiuretic effect, water reabsorption increases and oliguria may occur. Therefore, you need to be alert to the occurrence of water intoxication.

④Application of prostaglandin (PG): Prostaglandin E2 and F2α both have the effect of promoting uterine contraction. The routes of administration are oral, intravenous infusion and topical application (placed in the posterior fornix of the vagina). Intravenous infusion of PGE2 0.5μg/min and PGF2α 5μg/min can usually maintain effective uterine contraction. If uterine contractions are still not strong after half an hour, the dose can be increased as appropriate, with the maximum dose being 20 μg/min. The side effects of prostaglandins include excessive uterine contractions, nausea, vomiting, headache, tachycardia, blurred vision and superficial phlebitis, so they should be used with caution.

⑤Acupuncture points: has the effect of enhancing uterine contractions. Usually, acupuncture is performed on the Hegu, Sanyinjiao, Taichong, Zhongji, Guanyuan and other acupoints with strong stimulation techniques, and the needles are left in for 20 to 30 minutes. Auricular acupuncture can select acupoints such as uterus, sympathetic, and endocrine.

After the above treatment, if the labor process still does not progress or signs of fetal distress appear, cesarean section should be performed promptly.

(2) Second stage of labor: If there is no cephalopelvic disproportion in the second stage of labor and uterine atony occurs, uterine contractions should be strengthened and oxytocin should be given by intravenous drip to promote the progress of labor. If the biparietal diameter of the fetal head has passed the plane of the ischial spines, wait for natural delivery, or perform episiotomy, vacuum extraction or forceps delivery; if the fetal head has not yet engaged or there are signs of fetal distress, a cesarean section should be performed.

(3) Third stage of labor: To prevent postpartum hemorrhage, when the front shoulder of the fetus is exposed at the vaginal opening, 0.2 mg of ergonovine can be given by intravenous push, and 10-20 U of oxytocin can be given by intravenous drip at the same time to enhance uterine contraction, promote placental separation and delivery, and close the uterine blood sinusoids. If the labor is long and the membranes rupture for a long time, antibiotics should be given to prevent infection.

2. Uncoordinated uterine atony? The principle of treatment is to regulate uterine contraction and restore the polarity of uterine contraction. Give the strong sedative pethidine 100 mg or morphine 10-15 mg intramuscular injection to allow the mother to get enough rest. After waking up, she can usually recover coordinated uterine contractions. Oxytocin should not be used until uterine contractions have become coordinated. If the uncoordinated uterine contractions cannot be corrected after the above treatment, or are accompanied by signs of fetal distress or cephalopelvic disproportion, a cesarean section should be performed. If uncoordinated uterine contractions have been controlled but uterine contractions are still weak, methods to strengthen uterine contractions when coordinated uterine contractions are weak can be used.

The above content tells us in detail what we should do when the uterus contracts weakly. I believe that through the above content everyone has a certain understanding of what to do when the uterus contracts weakly. If you feel that what I have introduced is not detailed enough and you want to know more, you can ask our experts your questions through online communication.