Excessively strong labor activity is a clinical form of labor dysfunction, manifested by hyperactivity of the uterus: contractions of excessive intensity, their frequent alternation and increased tone of the myometrium. Pathology is characterized by a sudden onset, rapid course and rapid end of labor; at the same time, the risk of severe complications from the woman in labor and the fetus increases. Excessively strong labor activity is detected on the basis of observation of the dynamics of labor, CTG data. Tocolytic drugs, fluorotane or ether anesthesia are used to relieve generic dysfunction.
O62.8 Other labor disorders
The frequency of development in obstetric practice is 0.4-0.8% of cases from all births. Signs are excessive uterine tone (more than 12 mmHg) and pathologically strong contractions with an amplitude of more than 50 mmHg, lasting more than 1 minute, with an interval of less than 1-2 minutes.
With disease, the opening of the cervix progresses unusually quickly and the expulsion of the fetus from the uterus occurs just as rapidly. This pathology in all cases is accompanied by a violation of uteroplacental circulation and a related disorder of gas exchange in the fetus of varying severity. Often, as a result of the rapid contractile activity of the uterus, childbirth proceeds so rapidly that a woman does not have time to be delivered to a maternity hospital (the so-called “street childbirth”).
The etiofactors that cause are insufficiently studied. Such a violation of the birth forces usually develops against the background of increased general excitability of the nervous system in neurasthenia, hysteria, basedova disease, etc. It is assumed that excessively strong labor activity is due to violations of the cortico-visceral regulation of labor and the associated excessive formation of hormones and mediators (oxytocin, adrenaline, prostaglandins, acetylcholine, etc.), stimulating contractile activity of the uterine muscles.
In some women in labor, violent labor activity may be due to congenital pathology of myocytes – their increased excitability. With this disorder, the induction of uterine muscle contraction requires less than usual potential. Usually in such cases, excessively strong labor activity can be traced in the anamnesis of the mother of the woman in labor or her close relatives.
In the practice of obstetrics and gynecology, almost 50% of cases of excessively strong labor activity are registered during premature birth. Contribute to the development of excessively strong labor activity can:
- burdened obstetric and gynecological anamnesis: severe gestosis, endometritis, cervicitis, ovarian dysfunction, pathological previous childbirth, young (under 18 years old) or late (over 30 years old) age of the primiparous, uterine hypertonus and the threat of spontaneous termination of pregnancy;
- the existing anatomical obstacles to the expulsion of the fetus: the transverse position of the fetus, the narrow pelvis of the mother, etc.;
- unreasonable and excessive birth stimulation.
Childbirth, proceeding with excessively strong labor activity, usually begins suddenly. At the same time, vigorous contractions often follow each other with short pauses develop, which very quickly leads to the opening of the uterine pharynx. The woman in labor is in a state of excitement, which is expressed in increased motor activity, tachycardia, an increase in blood pressure, increased breathing.
Following the outpouring of amniotic fluid, violent attempts immediately develop; fetal birth often occurs within 1-2 attempts. With excessively strong labor activity, childbirth can be fast (4-6 hours for first–time births, 2-4 hours for repeat births) or rapid (2-4 hours for first–time births and less than 2 hours for repeat births).
The danger of excessively strong labor activity is a high risk of getting birth injuries, both by the woman in labor and by the child. Such an anomaly of the birth forces threatens premature detachment of the placenta, the occurrence of deep ruptures of the vulva, perineum, vagina, cervix and uterine body by the divergence of the pubic bones. The consequence of the rapid expulsion of the fetus may be uterine hypotension and postpartum bleeding threatening in intensity. Due to birth injuries, the risk of septic complications increases – metroendometritis, metrothrombophlebitis, etc. Sometimes this disease is replaced by a secondary weakness of the labor forces.
During an excessively strong labor activity due to a violation of the uteroplacental blood flow, the fetus experiences acute hypoxia. In addition, with rapid passage through the birth canal, the fetal head does not have time to be configured, being subjected to severe compression, which is often accompanied by injuries – damage to the skull, intracranial hemorrhages, etc.
The establishment of an excessively strong nature of labor activity is carried out on the basis of the above-mentioned signs.The course of the labor act is characterized by frequent, prolonged, intense contractions, rapid attempts immediately after the outpouring of water. Necessary diagnostic methods:
- Vaginal examination. Allows you to identify a high rate of opening of the uterine pharynx.
- Cardiotocography. According to the CTG, violent labor activity is registered.
- Assessment of fetal condition. Ultrasound, dopplerometry of uteroplacental blood flow, phonocardiography of the fetus can be used for a qualitative assessment of the biophysical profile of the fetus.
Excessively strong labor activity in the process of diagnosis is fundamentally important to differentiate from discoordinated labor activity. In the latter case, despite intense contractions, the cervix remains closed.
Treatment of excessively strong labor activity
When detecting excessively strong labor activity, the efforts of obstetricians and gynecologists are aimed at removing excessive contractile activity of the uterus. For this purpose, the woman in labor is placed on the side opposite to the position of the fetus.
- Drug therapy includes the administration of infusion of tocolytic drugs (beta-adrenomimetics: phenoterol, terbutaline, ritodrine, etc.), calcium antagonists, which reduce the intensity and frequency of contractions.
- Fluorotane or ether anesthesia, intramuscular injections of magnesium sulfate, trimeperidine, acupuncture are used to relieve labor.
- During the second period of labor, pudendal anesthesia is applied, an episiotomy or perineotomy is performed.
At the end of childbirth, a thorough examination of the birth canal is performed in order to identify ruptures and their suturing. With the development of uncupable postpartum bleeding, supravaginal amputation of the uterus (removal of the uterus without a cervix) or complete hysterectomy is indicated.
Patients with the threat of developing excessively strong labor activity during pregnancy should pay attention to psychoprophylactic preparation for childbirth, training in muscle relaxation techniques and auto-training skills. An important role is played by early detection and elimination of predisposing factors, compliance with the recommended rest and nutrition regime.
In the presence of this pathology in the anamnesis of a pregnant woman or her relatives, a woman is hospitalized in the maternity hospital in advance. In case of an unfavorable outcome of a previous pregnancy or the presence of a burdened obstetric-gynecological status, the question of caesarean section is raised in the interests of the mother and fetus in a planned manner. In the presence of indications, drug prevention of excessively strong labor activity with sedative, antispasmodic, metabolic drugs is carried out.