Leaking amniotic fluid is a pathological condition caused by a high rupture of the fetal membranes or the formation of microcracks in them. It is manifested by the constant release of a small amount of watery amniotic fluid. For diagnosis, examination with mirrors, amniotests, amniocentesis with a safe dye, examination of a vaginal smear under a microscope, transabdominal ultrasound are used. Obstetric tactics are determined by the period of pregnancy, the condition of the mother and fetus, the presence of complications. With expectant management, antibiotics, glucocorticoids, tocolytics are prescribed. Active tactics involve termination of pregnancy or induction of labor.
General information
Damage to the fetal egg with a slight leakage of water is observed in almost half of cases of premature rupture of the amnion. According to various authors, this pathological condition occurs in 2-5% of pregnancies and is the cause of almost 10% of cases of perinatal mortality. Due to minimal clinical manifestations, leakage is often not detected in time, which significantly increases the risk of infectious and other complications. It is the rupture of the membranes that provokes premature birth, is the main cause of prematurity, pulmonary hypoplasia and fetal sepsis — three key factors that increase the risk of death of a newborn. The use of modern diagnostic methods and rational management of pregnant women with damaged fetal membranes can significantly improve the prognosis for mother and child.
Causes of leaking amniotic fluid
The constant release of a small amount of amniotic fluid is observed when the integrity of the fetal membranes is violated. Unlike the abundant premature outpouring of amniotic fluid as a result of the rupture of the lower pole of the fetal egg, leakage usually occurs with the so-called high lateral tear or the formation of microcracks. There are several groups of causes that lead to damage to the amniotic membrane:
- Infectious processes. Spontaneous rupture of fetal membranes is more often observed in pregnant women suffering from endometritis, colpitis, cervicitis, adnexitis. The strength of the amnion is significantly reduced with chorioamnionitis.
- Disorders in the utero-placental system. The probability of damage to the amniotic sac increases in the presence of a two-horned or doubled uterus, cervical insufficiency, placental insufficiency, shell attachment or premature detachment of the placenta.
- Iatrogenic effects. Water leakage can be the result of multiple bimanual examinations, transvaginal ultrasound, amniocentesis, chorion biopsy and strengthening of the cervix with sutures at cervical insufficiency.
- Fetal factors. The walls of the amniotic bladder experience increased pressure during multiple pregnancies, fetal hydrocephalus, anomalies of its position and insertion of the adjacent part.
- Pathology of the membranes. Excessive stretching of the amnion occurs with polyhydramnios caused by primary and secondary hyperproduction of amniotic fluid or a violation of their resorption. The elasticity of the membranes also decreases with their hyaline degeneration (premature degeneration).
- Abdominal injuries. Fetal membranes can rupture with a sharp blow to the abdomen, penetrating wounds of the abdominal cavity and uterus.
Specialists in the field of obstetrics and gynecology identify a number of predisposing factors that increase the risk of spontaneous destruction of fetal membranes. The probability of leakage is higher in women with premature discharge of amniotic fluid during a previous pregnancy (relapse is observed in 20-30% of cases), in the presence of chronic inflammatory diseases of the genitals and scarring of the cervix. Pathology is more often diagnosed in patients who use glucocorticoid drugs for a long time, with systemic connective tissue diseases, anemia, nicotine addiction. According to some authors, a certain provoking role is played by a low level of well-being of a woman, which leads to an unbalanced diet, significant physical and psycho-emotional stress.
Pathogenesis
The key role in the pathogenesis of leaking amniotic fluid is played by the causes leading to damage to the amnion. The starting point of the process is usually structural changes in the membranes of the fetus caused by inflammation, degenerative changes or significant stretching. The starting point of the rupture, followed by leakage, is an excessive increase in the pressure of amniotic fluid or a sharp traumatic effect (shock, rough palpation, puncture) that violate the integrity of the membranes.
With a high lateral location, the defect of the amniotic sac is located above the internal uterine pharynx, therefore, the rate of leaking amniotic fluid is limited due to the proximity of the damaged area to the uterine wall. Since the ruptures of the amnion do not scar, the protective function of the fetal bladder decreases, the risk of infection of the fetus increases. In addition, the enzymes contained in the amniotic fluid can provoke placental abruption and, depending on the gestational age, spontaneous abortion or premature birth.
Classification
When choosing the tactics of management of a pregnant woman, the time of damage to the membranes of the fetus plays a decisive role. Based on this criterion, the following types of water leakage are distinguished:
- With premature prenatal rupture — up to 37 weeks of pregnancy (leakage during premature pregnancy);
- In case of prenatal rupture — from the 37th week of gestational age (leakage during full-term pregnancy);
- With an early lateral rupture — during childbirth before the opening of the neck by 4 cm or more.
Symptoms
If the outflow of amniotic fluid is not combined with another obstetric or gynecological pathology – there are no subjective sensations, the condition in some cases may remain unnoticed. The volume of the abdomen, as a rule, does not decrease. Usually a pregnant woman complains of a constant discharge from the vagina of a watery liquid without color and odor, the amount of which increases with a change in posture, abdominal tension during coughing, sneezing, physical exertion and in a horizontal position.
If a woman suspects water leakage, she can use a simple “clean diaper” method. The appearance of a wet spot on the fabric after lying on your back for 30-60 minutes is a reason for an urgent appeal to a women’s consultation. With ruptures lasting more than a day, signs of infection of the uterus, fetus and / or its membranes appear and increase. The patient’s body temperature rises to 38 degrees or more, chills occur, pains in the lower abdomen, which increase with palpation. An admixture of pus and sucrovitsa may appear in the vaginal discharge.
Complications
Prolonged leakage of amniotic fluid poses a significant threat to both the pregnant woman and the fetus. According to a number of researchers, with this pathology, the risk of stillbirth increases by 8-13 times, perinatal mortality increases by 4 times, and neonatal morbidity increases by 3. The main complications with a high risk of fetal death and newborn death are respiratory distress syndrome, chorioamnionitis, necrotizing enterocolitis, intraventricular hemorrhages. Due to a violation of uteroplacental circulation, fetal hypoxia occurs. Premature detachment of the child’s place and congenital anomalies (retinopathy, open arterial duct, skeletal deformity, limb self-amputation, etc.) are possible. In pregnant women with leaking amniotic fluid, weakness of labor activity, postpartum bleeding and endometritis are more often observed.
Diagnostics
The leakage of amniotic fluid is one of the most difficult in terms of the diagnosis of pathological conditions during pregnancy. Poor clinical symptoms and a high risk of subsequent complications require a particularly thorough examination of patients with suspected damage to the membranes of the fetus. Diagnostic measures are aimed at confirming the amniotic nature of the discharge and identifying possible complications. The survey plan usually includes:
- Inspection in mirrors. In the posterior arch, a small amount of transparent liquid is determined, which leaks when coughing a pregnant woman.
- Transabdominal ultrasound. With leakage, this method is less informative, but it allows you to diagnose possible complications in time — placental abruption, signs of fetal suffering, etc.
- Vaginal smear microscopy. The presence of amniotic fluid is indicated by crystallization in the form of characteristic fern leaves. However, this method is considered insufficiently sensitive and specific.
- Amniotest. Changes in the color of the test strips are revealed by the alkalinization of the acidic environment of the vagina by amniotic fluid, and the detection of placental microglobulin in the secretions in 99.9% of cases indicates damage to the fetal membranes.
- Amniocentesis with dye. The method is highly invasive and involves the introduction of a safe dye into the amniotic sac through a puncture of the abdominal wall. If, 20-30 minutes after insertion, a tampon inserted into the vagina is stained, the diagnosis of rupture of the membranes is considered confirmed.
Differential diagnosis is performed with inflammatory diseases of the female genital organs (vaginitis, cervicitis, endometritis, salpingoophoritis), amnionitis, premature placental abruption. When complications are detected, an anesthesiologist, a neonatologist, and a therapist are involved in the management of the patient.
Treatment of leaking amniotic fluid
When choosing a management scheme for a pregnant woman, the gestation period is taken into account first of all. Taking into account the non-viability of the fetus and the high risk of dangerous complications, it is recommended to terminate pregnancy before 22 weeks. Patients are hospitalized at a later date in obstetric hospitals of the 3rd level and provide maximum physical rest. From 22 to 34 weeks inclusive, the tactics are wait-and-see. Prolongation of pregnancy is contraindicated in chorioamnionitis, gross malformations, acute hypoxia or fetal death, the onset of labor, preeclampsia and eclampsia, placental abruption and a number of other conditions. In other cases, recommended:
- Preventive antibacterial therapy. To reduce the risk of infectious complications, antibiotics are prescribed by the course from the first day of hospitalization.
- Drugs for the prevention of RDS. Glucocorticoids are used to accelerate the synthesis of surfactant and the maturation of lung tissue.
- Tocolytic therapy. The use of selective β2-adrenomimetics, magnesium sulfate, cyclooxygenase inhibitors, slow calcium channel blockers and oxytocin receptors reduces the contractile activity of the myometrium.
- Amniotransfusion. It is used in exceptional cases at the request of a pregnant woman at 22-24 weeks with large volumes of secretions and a significant decrease in the amount of amniotic fluid.
Treatment is carried out against the background of regular monitoring of the condition of the fetus and pregnant woman: thermometry, assessment of blood and hemodynamics, daily cardiotocography, weekly ultrasound, dopplerometry of fetoplacental blood flow every 3 days. At the same time, special attention is paid to the prevention of nosocomial infection.
When detecting water leakage in a woman with a 34-36-week pregnancy, both expectant and active tactics are used. Since there is no reliable data that the induction of labor at this time worsens the neonatal outcome, the second option is preferable. Waiting often provokes the development of chorioamnionitis and umbilical cord compression. The duration of observation usually does not exceed 1 day. After the onset of labor, antibiotics are prescribed for prophylactic purposes.
At 37 weeks or more of gestation, when amniotic fluid is detected in the discharge and there is no labor activity, stimulation of labor is shown. Antibacterial therapy is used in the diagnosis of chorioamnionitis. Preventive administration of antibiotics is recommended only in cases where the expected duration of water leakage exceeds 18 hours.
Prognosis and prevention
The prognosis for leaking amniotic fluid depends on the duration of pregnancy. Rational use of wait-and-see tactics allows the fetus to mature as much as possible and minimizes the risk of infectious complications. The cessation of leakage at 22-33 weeks of pregnancy allows you to prolong it to full-term, if the condition of the woman and the fetus is satisfactory, and the amount of amniotic fluid remains at a normal level. With continued leakage of water, no signs of inflammation, satisfactory condition of the pregnant woman and fetus, prolongation is possible for no more than 1-3 weeks. The risk of perinatal mortality significantly decreases with premature birth from 31-33 weeks of pregnancy, and the incidence of newborns — from 34 or more. Prevention of premature leakage of water provides for the restriction of heavy physical exertion, smoking cessation, timely registration and regular visits to an obstetrician-gynecologist, reasonable appointment of invasive diagnostic procedures (especially when risk factors are detected).
