Patient counseling following periviable premature rupture of the membranes
Periviable PROM refers to a rare condition defined by amniochorionic membrane rupture between 20 0/7 and 25 6/7 weeks’ gestation. Rates of perinatal and neonatal morbidity and mortality are high in pregnancies complicated by periviable PROM. Patients are most often presented with three management options following periviable PROM: pregnancy termination, indicated delivery, or expectant management. This article summarizes the etiology of periviable PROM and an approach to managing such complicated patients.
Diagnosis/definition: Premature rupture of membranes (PROM) is a condition characterized by rupture of the amniochorionic membranes prior to the onset of labor. Periviable PROM refers to instances of PROM occurring between 20 0/7 and 25 6/7 weeks’ gestation.
Epidemiology/Incidence: Although less than 1% (approximately 0.4%) of pregnancies are affected by this complication, the neonatal and maternal outcomes, along with the psychological and socioeconomic impacts, can be devastating.
Risk factors/associations: Retrospective studies have identified risk factors for periviable PROM that include intrauterine infection, history of cervical insufficiency, cerclage, antepartum bleeding, multifetal gestation, history of prior pregnancy affected by PROM or preterm labor, smoking, and both amniocentesis and fetoscopy.
Complications: Rates of perinatal and neonatal morbidity and mortality are high in pregnancies complicated by periviable PROM. Although the live birth rate for pregnancies affected by periviable PPROM is approximately 50% (mean 47%–56%) the survival to discharge rate is only 26.3%.Respiratory distress syndrome, neonatal sepsis, and severe intraventricular hemorrhage are the most common contributors to neonatal mortality. These causes are not specific to periviable PROM, but rather, to delivery at the extremes of prematurity. Adverse neonatal outcomes specific to periviable PPROM most commonly result from chronic oligohydramnios, and include pulmonary hypoplasia, limb deformities (eg, clubbed feet) and other components of fetal compression syndrome.
Prevention:A detailed evaluation focusing on the potentially modifiable causes of periviable PROM is of particular importance (eg, smoking or cervical insufficiency). A discussion regarding the potential benefits and risks of progestogens supplementation (17 OHPC 250 mg IM weekly starting at 16 weeks) and sonographic cervical length screening for future pregnancies is appropriate.
- Patient counseling: The duration of the latency period appears to be inversely related to the gestational age at which PROM occurs, with longer latency periods reported in pregnancies affected by PROM at earlier gestational ages. Obstetric providers should carefully review the potential maternal and neonatal outcomes with the woman and any involved family members before either active or expectant management is chosen.
- Prenatal care:The primary goals of expectant management are to prolong latency and improve neonatal outcomes while limiting maternal risk. Multiple antenatal interventions that have been shown to improve outcomes for pregnancies >24 weeks (antenatal corticosteroids, antibiotics, and magnesium sulfate for neuroprotection) have unknown effectiveness for those <24 wks since most clinical trials testing these interventions have not included pregnancies <24 wks.
Treatment: Patients are most often presented with three management options following periviable PROM: pregnancy termination, indicated delivery, or expectant management. There is currently no accepted definitive treatment to attempt correction of periviable PROM.
Delivery: Development of intrauterine infection is the primary cause leading to delivery, with placental abruption and nonreassuring fetal testing the next-most-common indications.