False contractions are irregular uterine contractions, in which painful sensations occur, but there is no opening of the cervix. They occur in late pregnancy, more often after the 20th week. Main manifestations: cramping pains in the lower abdomen or in the lumbar region without a clear periodicity. Methods of diagnosis of this condition are cardiotocography, examination of the cervix in mirrors to determine its degree of maturity, ultrasound of the genitals with an assessment of uterine blood flow. Specific treatment depends on the duration of pregnancy and the causes that caused this condition.
ICD 10
O47 False contractions
General information
False contractions are otherwise called “training” or “Braxton-Hicks contractions” after the English doctor who first described this phenomenon. Back in 1872, he noted that many women feel such contractions long before the expected birth. This caused concern and confusion among women in connection with the timing of actual childbirth, so J. Braxton Hicks began to warn pregnant women in advance about the possibility of such a phenomenon. False contractions are normally found in 33% of pregnant women. Repeat births feel false contractions at an earlier date compared to primiparous ones.
Causes
The contractile activity of the uterus depends on the work of the pituitary gland. In the late stages (from 37 weeks), the preparation of the body for future childbirth gradually begins, hormones with contractile ability (oxytocin, cortisone-like substances) are released. Under their influence, contractions occur periodically in the myometrium. At an early stage of gestation , the causes of false contractions may be:
- Pathology of the pituitary gland and endocrine glands. An increased content of thyroid hormones, adrenal glands, and the posterior pituitary gland in the blood can increase the readiness of muscle cells to contract. An increase in the level of prolactin provokes excessive formation of male steroid hormones in the female body, which can also lead to false contractions.
- Hypertonus of the uterus. Increased readiness of the myometrium to contractions before the due date can be caused by various factors. Both hormonal causes (reduced progesterone levels) and changes in fetal-uterine blood flow (by the type of uterine muscle hypoxia) play a role here.
- Underdevelopment of the neuro-receptor apparatus of the uterus. The ratio of the number of receptors to estrogen and progesterone is not constant and normally changes at different stages of pregnancy. A pathological increase in the number of estrogen receptors contributes to the occurrence of premature uterine contractions.
The risk group for the occurrence of false contractions in the early stages of pregnancy includes patients with gestosis, congenital anomalies of the genital apparatus and immune diseases. The development of false contractions is facilitated by overgrowth of the uterus during multiple pregnancies or the presence of a postoperative scar. Very often, pathological contractile activity of the muscular layer of the uterus is observed with intrauterine infection and cervical insufficiency.
Pathogenesis
In the last month of pregnancy, the contractile activity of the myometrium increases. The synthesis of biologically active substances and hormones that stimulate the tension of muscle fibers increases. The number of nerve impulses stimulating uterine contractions increases. In the brain, a focal point coordinating labor activity is formed — the “dominant of labor”.
Periodically occurring during this period, false contractions contribute to maintaining normal uterine tone and stimulating fetoplacental blood flow. Placental vessels do not have their own muscle layer, periodic uterine contractions displace venous blood from them, which is replaced by arterial blood. Thus, the fetus receives more oxygen and nutrients.
Symptoms of false contractions
False contractions are felt by a pregnant woman as an irregular tension in the lower abdomen. The sensations may resemble discomfort during menstruation. Pains of a pulling, aching nature can spread to the lumbar region, sometimes they are joined by a feeling of bursting in the genital area. The stomach during the fight becomes dense, rounded, “petrifies”. With a high pain threshold, Braxton-Hicks contractions may not be felt at all and may be detected accidentally, for example, during a doctor’s appointment.
False contractions begin and end suddenly, they have no clear rhythm. Seizures are more likely to develop at night, when the production of oxytocin increases in the pituitary gland. What distinguishes them from true contractions is that the strength of contractions does not increase over time, and the intervals between contractions do not decrease. False contractions take place when changing positions or stopping physical activity. They can occur and end several times a day.
Diagnostics
The presence of Braxton-Hicks training contractions can be suspected already on the basis of the patient’s complaints. During the examination, the tone of the uterus is assessed, which often strains in response to palpation. An examination in mirrors is required to determine the degree of maturity of the cervix and its length. If it is shorter than 25 mm, then this is considered a risk of premature birth and requires appropriate therapy (installing a pessary, applying a circulator).
A smear on the flora is taken from the genital tract of a pregnant woman, a nitrazine test is performed to exclude spotting, infection or leakage of amniotic fluid. To assess the general condition of the expectant mother, laboratory tests are carried out, such as a general urine and blood test, a biochemical study, an assessment of the excretory function of the kidneys. The patient is consulted by a general practitioner, if necessary by a nephrologist and an endocrinologist.
Methods of assessing the state of the uterus and fetus are used as special studies. It is very important to examine the placenta for functional viability, location and intensity of blood flow. To do this , it is carried out:
- Cardiotocography. At the same time, it allows you to track the contractile activity of the uterus, the presence of contractions and the state of fetal cardiac activity. Based on the results, it is possible to decide whether the fetus suffers from lack of oxygen during labor.
- Doppler ultrasound of the fetal-uterine blood flow. During the study, anomalies of the vascular bed of the placenta, uterus, fetus are revealed. Sometimes there is premature “aging” of the placenta, because of this, the level of blood circulation decreases, hypoxic conditions may develop in the fetus or in the myometrium, which serve as the causes of abnormal contractions.
Treatment
Treatment tactics are selected depending on the gestation period at which false contractions occurred. Starting from 37 weeks of gestation, with normal tests, the treatment of false contractions is not carried out. From 22 to 37 weeks, therapy is primarily aimed at eliminating the cause of uterine contractions. With endocrine pathology, hormonal correction is prescribed, maintaining an adequate level of progesterone, as the main hormone prolonging pregnancy.
With an increased tendency of the uterus to contractions, tocolytic (relaxing myometrium) is performed therapy. A proven remedy is magnesium sulfate (magnesia). With intravenous and intramuscular administration, it has an anticonvulsant effect. In addition, the drug prevents fluid retention in the pregnant woman’s body and activates the fetal-uterine blood flow. Sometimes the administration of the drug is used as a diagnostic test: false contractions stop at the same time, but it does not affect true contractions.
Also, selective beta-adrenomimetics (hexoprenaline), prostaglandin synthesis inhibitors (indomethacin) and antispasmodics (drotaverine) are used from tocolytics according to indications. Cytoprotectors and antiplatelet agents (pentoxifylline) are prescribed to prevent intrauterine fetal hypoxia and circulatory disorders in the uterus and placenta.
Prognosis and prevention
False contractions do not lead to the onset of labor, so the prognosis for pregnancy is favorable. In most cases, false contractions are part of the normal process of preparing for childbirth. If they are caused by a complicated course of pregnancy, it is important to be examined in time and carry out adequate treatment. To prevent false contractions of a pregnant woman, it is recommended to avoid excessive physical exertion and stressful situations. Also, for the coordinated work of the pituitary gland and the endocrine glands, it is necessary to observe the daily routine and a full sleep.
