Snapshot A 30-year-old G2P1 woman at 33 weeks of gestation presents to the emergency department saying that her "water broke." She reports that the fluid is a pale yellow color and denies the presence of mucus or blood. External fetal monitoring reveals a reactive fetal heart tracing and no uterine contractions. Speculum exam reveals a closed cervical os with a pool of fluid in the vaginal vault. A swab of her vaginal secretions is obtained and fixed to a glass slide; the view under the microscope is seen in the image. Bedside sonogram shows oligohydramnios and a fetus with cephalic presentation. Introduction Overview premature rupture of membranes (PROM) occurs when a patient at ≥ 37 weeks of gestation presents with rupture of membranes (ROM) prior to the start of uterine contractions preterm premature rupture of membranes (PPROM) describes PROM that occurs < 37 weeks of gestation Epidemiology Incidence ~10% of all pregnancies Risk factors urinary tract infection antepartum bleeding low body mass index cigarette smoking cerclage amniocentesis ETIOLOGY Pathophysiology Ruptured membranes at term result from programmed cell death, activation of collagenase, and mechanical forces premature rupture of membranes occurs due to premature activation of these pathways may be linked to underlying inflammation and/or infection of the membranes Presentation Symptoms leakage of fluid from the vagina in the absence of contractions vaginal discharge vaginal bleeding pelvic pressure Physical exam avoid digital vaginal examination observation of pooling of fluid in the vaginal fornix on speculum examination most accurate observation for the diagnosis of ROM Studies Vaginal fluid Fern test vaginal fluid is swabbed and placed on a glass slide ferning of the dried fluid under microscopic examination indicates the presence of amniotic fluid Nitrazine paper test tests the pH of the vaginal fluid paper turns blue when pH is > 6 vaginal fluid is acidic with a pH ~4, while amniotic fluid has a pH ~7 Tested Differential Urinary incontinence key distinguishing factor leakage of urine Increased cervical discharge from infection key distinguishing factor negative fern and nitrazine paper test Treatment Medical observation, antibiotic administration, and antenatal corticosteroid administration indications if there is no evidence of chorioamnionitis or fetal compromise in patients at 22-34 weeks of gestation technique antibiotics administer antibiotic regimen to reduce the risk of chorioamnionitis and neonatal sepsis erythromycin or amoxicillin-clavulanic acid are commonly used corticosteroids given to promote lung development if the lecithin/sphingomyelin ratio is < 2.0, can administer betamethasone up to < 36 weeks of gestation induce delivery indications if > 34 weeks of gestation, unless the gestational age of the fetus is uncertain and fetal maturity cannot be confirmed Complications Chorioamnionitis incidence from < 10% during the first 24 hours of PROM to as high as 40% after 24 hours treatment adminstration of intrapartum antibiotics and antipyretics Fetal/neonatal death incidence 1% of all patients with PROM 0.001% of patients with PROM at term Prognosis Generally good if occurring > 32 weeks of gestation 90% of patients enter spontaneous labor within 24 hours if ROM occurs at term