Pathological preliminary period of labor is a prolonged prenatal preparatory period that proceeds with irregular painful contractions that do not lead to structural changes in the cervix. The pathological preliminary period is characterized by prolonged (over 6-8 hours) continuing ineffective cramping pains that disrupt the daily waking and sleeping regime of a woman, cause fatigue of a woman in labor and increase the risks of fetal hypoxia. Diagnosis of the preliminary period of labor includes vaginal examination, cardiotocography. In order to remove the abnormal preliminary period of labor, anesthesia, drug sleep, the introduction of beta-adrenomimetics are used; sometimes – cesarean section.
Clinical manifestations of the physiological (uncomplicated) preliminary period of labor, lasting on average 5-8 hours, are poorly expressed; periodic pulling and cramping pains in the lower abdomen and sacrum do not change the general well-being of a woman. Normal preliminary contractions (false contractions, forerunner contractions) can stop and resume after a day, but more often they gradually intensify, become more frequent and turn into regular labor activity. At the end of the physiological preliminary period, maturation (shortening and softening) of the cervix is observed, the cervical canal is slightly opened by 2-3 cm.
The incidence of pathology in the preliminary period of labor is 10-17%. With the development of a pathological preliminary period, the latent phase of labor is delayed and can last from 6-8 hours to 24-48 hours or longer. Spastic contractions in this case occur against the background of increased myometrial tone; in strength, frequency and soreness are comparable to true labor, but do not lead to maturation of the cervix. Obstetrics and gynecology the pathological preliminary period of labor is regarded as hypertensive dysfunction of the uterus. The pathological preliminary period of labor can turn into weak or discoordinated labor activity.
Violations of the preliminary period of labor are more often noted in the pathology of the maternal organism: in pregnant women with labile nervous system, neuroses, NCD; metabolic and endocrine disorders (obesity, underweight, menstrual dysfunction, sexual infantilism, etc.); concomitant somatic pathology (heart defects, arrhythmia, arterial hypertension, kidney, liver, adrenal gland diseases); inflammatory changes of the uterus (endometritis, cervicitis); gestosis, dystrophic processes after abortions.
In addition, a woman’s negative attitude towards the birth of a child, fear of childbirth, the age of first-time mothers younger than 17 or older than 30 years can contribute to the prolongation of the preliminary period. Obstetric causes of the complicated prelim period of labor include multiple, low- or high-water pregnancy, large fetus, placenta previa, incorrect fetal positions, anatomically narrow pelvis, etc.
The pathologically proceeding preliminary period of labor is characterized by a sharp spastic contraction of the myometrium, leading to the appearance of painful contractions, their protracted course, which does not turn into regular labor activity. Despite the duration and severity of contractions, the cervix remains dense and long, and the cervical canal does not open. The excitability and tone of the uterus are sharply increased; uterine contractions are monotonous, without a tendency to increase and increase.
The pregnant woman’s condition is disturbed; the woman gets tired, cannot fall asleep and rest due to constant pain and emotional tension, becomes irritable and unbalanced. A pregnant woman may notice sweating, pain in the sacrum and lower back, shortness of breath, tachycardia, intestinal dysfunction.
The pathological preliminary period of labor is often complicated by prenatal discharge of amniotic fluid, anomalies of labor activity, the appearance and increase of signs of intrauterine fetal hypoxia. In some cases, after the outpouring of amniotic fluid, regular contractions appear and labor activity independently normalizes.
An external obstetric examination determines the high location of the adjacent part of the fetus, which is located high above the entrance to the pelvis; the tone of the uterus is increased, especially in its lower segment. Carrying out a vaginal examination in the pathology of the preliminary period of labor can be difficult due to the strong tension of the perineal muscles. During internal gynecological examination, there is a spasm of the vaginal muscles and immaturity of the cervix.
During cardiotocography, contractions of different duration and strength, unequal time intervals between them, the predominance of the tone of the lower segment of the uterus over the tone of the bottom and body are recorded. Cytological examination of the vaginal smear indicates insufficient estrogenic saturation of the body.
Tactics in the pathological preliminary period of labor
Tactics in the pathological course of the preliminary period of labor is determined by its duration, the condition of the pregnant woman, the severity of the clinic, the condition of the fetus and the birth canal. In all situations accompanying the pathological preliminary period of labor, the use of estrogens, analgesics, sedatives, and antispasmodics is indicated.
If the preliminary period of labor lasts less than 6 hours, is accompanied by the maturity of the cervix and the standing of the fetal head at the entrance to the pelvis, treatment begins with electroanalgesia or acupuncture. With a preserved fetal bladder and the maturity of the birth canal, an amniotomy is performed. In the case of the duration of the preliminary period of labor up to 6 hours, but the immaturity of the cervix, sedation (administration of diazepam) and medication preparation of the cervix (administration of prostaglandins E2, estradiol dipropionate, estrone, etc.) is indicated.
With a prolonged preliminary period of labor (10-12 hours or more), accompanied by fatigue of the woman in labor, medication sleep is used. After awakening, 85% of women have an active labor phase with normal contractile activity of the uterus. In the remaining 15%, due to the absence or lack of expression of contractions, careful administration of uterotonics (oxytocin, prostaglandin) is indicated. In addition to all of the above, beta-adrenomimetics (hexoprenaline, terbutaline, phenoterol, etc.) are used to relieve the pathological preliminary period of labor.
If it is impossible to achieve active and regular labor, as well as with a burdened obstetric history, a large fetus, pelvic presentation, extragenital diseases, signs of fetal hypoxia, it is advisable to carry out delivery by caesarean section. The maximum duration of treatment of the pathological preliminary period of labor should not exceed 3-5 days.
To exclude the abnormal course of the preliminary period of labor, competent preparation and management of pregnancy, compliance with the prescribed regimen by a woman, psychoprophylactic preparation for childbirth is necessary.
Special attention of the obstetrician-gynecologist should be directed to the contingent of pregnant women who constitute a risk group for the development of a pathological prelim period of childbirth – first-time mothers of young and older age, women with a burdened obstetric and gynecological history, chronic genital inflammation; neuroendocrine, somatic and neuropsychiatric disorders; anatomical inferiority of the uterus; fetoplacental insufficiency; polyhydramnios, multiple births or large the fruit.