Cramping contractions (tetany, or uterine fibrillation)

Spasmodic contractions are characterized by prolonged contraction of the uterine muscles. In tetany of the uterus, contractions follow one after another, there are no pauses between them. When tetany occurs, the frequency of contractions increases (more than 5 contractions in 10 minutes), their intensity progressively decreases, and hypertonicity of the uterus quickly increases due to incomplete relaxation. The latter remains at high levels for a long time, and contractions are practically not detected. Then the tone of the uterus slowly and gradually decreases to a normal level, and as it decreases, the intensity of contractions increases.

The cause of the appearance of convulsive contractions of the uterine muscles may be:

• clinical inconsistency;
• premature detachment of the placenta;
• repeated attempts at obstetric version, application of obstetric forceps, extraction of the fetus by the pelvic end;
• other interventions without anesthesia, performed unsuccessfully due to the lack of obstetric conditions or knowledge of surgical technique.

Spastic contractions of the uterine muscles may occur when ergot preparations are prescribed during labor, or when there is an overdose of quinine hydrochloride, oxytocin, and other medications.

In case of uterine tetany, the condition of the intrauterine fetus suffers sharply.

Clinically, uterine tetany is manifested by general anxiety, incessant distending abdominal pain, lack of relaxation of the uterus, sometimes complaints of tenesmus from the bladder and rectum, small portions of stagnant urine are released during catheterization of the bladder, a feeling of pressure on the bottom, increased pulse rate, pain in the lumbosacral region. On palpation, the entire uterus is of stony density, painful, its shape is changed. It is not possible to palpate part of the fetus and its presenting part. Vaginal examination reveals tension of the pelvic floor muscles, narrowing of the vagina, edematous edges of the cervical os. If the fetal bladder is intact, it is stretched over the presenting part. In the absence of the fetal bladder, a pronounced labor tumor is noted, making it difficult to determine the sutures and fontanelles.

In this form of pathology, uteroplacental blood circulation and gas exchange in the fetus are sharply disrupted, which manifests itself as intrauterine hypoxia. The fetal heartbeat is usually not heard or is heard with difficulty. Labor is suspended.

The diagnosis can be established based on the clinical picture provided. Hysterography shows that the frequency of contractions increases sharply and the tone of the uterus increases, while contractions are practically not detected and this condition can continue for a significant period of time (up to 10 minutes or more). Then the tone of the uterus gradually decreases to a normal level, and as it decreases, the intensity of contractions increases.

Treatment of uterine tetany depends on its cause. Thus, in case of an overdose of oxytotic agents, their administration should be stopped immediately and, if necessary, the woman in labor should be given deep anesthesia with ether or fluorothane or urgently administer intravenous beta-adrenergic agonists (partusisten or brikanil, etc.).

In case of clinical discrepancy, after anesthesia, a cesarean section should be performed (sometimes on a dead fetus). Obstetric anesthesia usually removes tetany and normalizes labor. If the birth canal is prepared, the fetus is extracted under anesthesia using obstetric forceps or by the leg (in case of breech presentation). In case of a dead fetus, a craniotomy operation is performed. After the fetus is extracted, manual separation of the placenta, separation of the placenta and examination of the uterine cavity are indicated to exclude rupture.

In case of uterine tetany, fetal hypoxia and lack of conditions for vaginal delivery, a cesarean section is indicated.

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