Преждевременное излитие околоплодных вод: причины, диагностика и тактика ведения.

Most women will experience a painless leakage of fluid out of the vagina. They may notice either a distinct "gush" or a steady flow of small amounts of watery fluid in the absence of steady uterine contractions.

The cause of PROM is not clearly understood, but the following are risk factors that increase the chance of it occurring. In many cases, however, no risk factor is identified. Infections: urinary tract infection, sexually transmitted diseases, lower genital tract infections (e. g. bacterial vaginosis),
Cell death: when cells undergo programmed cell death, they release biochemical markers that are detected in higher concentrations in cases of PPROM. Poor assembly of collagen: collagen is a molecule that gives fetal membranes, as well as other parts of the human body such as the skin, their strength. In cases of PPROM, proteins that bind and cross link collagen to increase its tensile strength are altered. Breakdown of collagen: collagen is broken down by enzymes called matrix metalloproteinases (MMPs), which are found at higher levels in PPROM amniotic fluid. This breakdown results in prostaglandin production which stimulates uterine contractions and cervical ripening. MMPs are inhibited by tissue inhibitors of matrix metalloproteinases (TIMPs) which are found at lower levels in PPROM amniotic fluid.

Many genes play a role in inflammation and collagen production, therefore inherited genes may play a role in predisposing a person to PROM. Prolonged PROM: a case of prelabor rupture of membranes in which more than 18 hours has passed between the rupture and the onset of labor. Preterm prelabor rupture of membranes (PPROM): prelabor rupture of membranes that occurs before 37 weeks gestation. Midtrimester PPROM or pre viable PPROM: prelabor rupture of membranes that occurs before 24 weeks' gestation. Before this age, the fetus cannot survive outside of the mother's womb.

The following tests should only be used if the diagnosis is still unclear after the standard tests above. Ultrasound: Ultrasound can measure the amount of fluid still in the uterus surrounding the fetus. If the fluid levels are low, PROM is more likely.

When the fetus is 34 to 37 weeks gestation, the risk of being born prematurely must be weighed against the risk of PROM. Previously it was recommended that delivery be carried out as if the baby was term.

Monitoring for infection: signs of infection include a fever in the mother, fetal tachycardia (fast heart rate of the fetus, more than160 beats per minute), or tachycardia in the mother (more than 100 beats per minute). White blood cell (WBC) counts are not helpful in this case because WBC's are normally high in late pregnancy. The American Congress of Obstetricians and Gynecologists (ACOG) recommends a seven day course of intravenous ampicillin and erythromycin followed by oral amoxicillin and erythromycin if watchful waiting is attempted before 34 weeks. Home care: Typically women with PPROM are managed in the hospital, but, occasionally they opt to go home if watchful waiting is attempted. Since labor usually starts soon after PPROM, and infection, umbilical cord compression, and other fetal emergencies can happen very suddenly, it is recommended that women stay in the hospital in cases of PPROM after 24 weeks. Sealing membranes after rupture: Infection is the major risk associated with PROM and PPROM. By closing the ruptured membranes, it is hoped that there would be a decrease in infection, as well as encouraging the re accumulation of amniotic fluid in the uterus to protect the fetus and allow for further lung development. Common techniques include placing a sponge over the ruptured membrane and the use of oral autoimmune stimulating drugs to encourage the body's immune system to repair the rupture. There is currently insufficient research to determine whether these or other resealing techniques improve maternal or neonatal outcomes when compared to the current standard of care.

Before 24 weeks, a fetus is not viable meaning it cannot live outside the mother. In this case, either watchful waiting at home or an induction of labor done. Antenatal corticosteroids, latency antibiotics, magnesium sulfate, and tocolytic medications are not recommended until the fetus reaches viability (24 weeks). PROM provides a path for disease causing organisms to enter the womb and puts both the mother and baby at risk for infection. Low levels of fluid around the baby also increase the risk of umbilical cord compression and can interfere with lung and body formation of the baby in early pregnancy. PROM is responsible for 20% of all fetal deaths between 24 and 34 weeks' gestation.

Before 24 weeks the fetus is still developing its organs, and the amniotic fluid is important for protecting the fetus against infection, physical impact, and for preventing the umbilical cord from becoming compressed. It also allows for fetal movement and breathing that is necessary for the development of the lungs, chest, and bones. Low levels of amniotic fluid due to mid trimester or previable PPROM (before 24 weeks) can result in fetal deformity (e. g. Potter like facies), limb contractures, pulmonary hypoplasia (underdeveloped lungs), infection (especially if the mother is colonized by group B streptococcus or bacterial vaginosis), prolapsed umbilical cord or compression, and placental abruption.

Most cases of PROM occur spontaneously, but the risk of PROM in women undergoing a second trimester amniocentesis for prenatal diagnosis of genetic disorders is 1%. Although no studies are known to account for all cases of PROM that stem from amniocentesis. This case, the chances of the membranes healing on their own and the amniotic fluid returning to normal levels is much higher than spontaneous PROM. Compared to spontaneous PROM, about 70% of women will have normal amniotic fluid levels within one month, and about 90% of babies will survive.

Of term pregnancies (more than 37 weeks) about 8% are complicated by PROM, 20% of these become prolonged PROM. About 30% of all preterm deliveries (before 37 weeks) are complicated by PPROM, and rupture of membranes before viability (before 24 weeks) occurs in less than 1% of all pregnancies. Since there are significantly fewer preterm deliveries than term deliveries, the number of PPROM cases make up only about 5% of all cases of PROM.