Prematurity from any cause leads to 75% of perinatal mortality and about 50% of all long-term morbidity. PROM is responsible for 20% of all fetal deaths between 24 and 34 weeks gestation. Fetal development (before 24 weeks)
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. PROM after second-trimester amniocentesis
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. Epidemiology
Of term pregnancies (more than 37 weeks) about 8% are complicated by PROM, 20% of these become prolonged PROM.
In cases of pre-viable PPROM, chance of survival of the fetus is between 15 and 50%, and the risk of chorioamnionitis is about 30%. Chorioamnionitis
Chorioamnionitis is a bacterial infection of the fetal membranes, which can be life-threatening to both mother and fetus. Women with PROM at any age are at high risk of infection because the membranes are open and allow bacteria to enter. Women are checked often (usually every 4 hours) for signs of infection: fever (more than 38 °C or 100.5 °F), uterine pain, maternal tachycardia, fetal tachycardia, or foul-smelling amniotic fluid. Elevated white blood cells are not a good way to predict infection because they are normally high in labor. If infection is suspected, artificial induction of labor is started at any gestational age and broad antibiotics are given. Caesarean section should not be automatically done in cases of infection, and should only be reserved for the usual fetal emergencies. Outcomes
The consequences of PROM depend on the gestational age of the fetus. When PROM occurs at term (after 36 weeks), it is typically followed soon thereafter by the start of labor and delivery. About half of women will give birth within 5 hours, and 95% will give birth within 28 hours without any intervention. The younger the baby, the longer the latency period (time between membrane rupture and start of labor).