Outcome of pregnancies complicated by ruptured membranes after genetic amniocentesis

OBJECTIVE: We sought to compare perinatal outcomes of pregnancies complicat ed by preterm premature rupture of membranes after genetic amniocentesis wi th pregnancies complicated by spontaneous preterm premature rupture of memb ranes at a similar gestational age. STUDY DESIGN: A retrospective study was performed in which a computerized d atabase was reviewed to identify all patients presenting to our institution with preterm premature rupture of membranes within 48 hours of a genetic a mniocentesis from July 1988 to August 1999. Control subjects were matched f or gestational age at preterm premature rupture of membranes. Patients were all managed expectantly Outcomes were compiled from review of medical reco rds. Descriptive statistics, the Student t test, and the chi (2) test were used, with P < .05 considered significant. RESULTS: During the study period, genetic amniocentesis was performed 1101 times. Eleven (1%) women presented within 48 hours with preterm premature r upture of membranes. The mean gestational age at the time of rupture was no t different between the cases in which preterm premature rupture of membran es occurred after genetic amniocentesis compared with the control subjects in whom preterm premature rupture of membranes occurred spontaneously (16.5 weeks vs 17.6 weeks, respectively). Women with preterm premature rupture o f membranes after amniocentesis experienced significantly longer latency pe riods (124 vs 28 days; P = .0001) and delivered at more advanced gestationa l ages (34.2 vs 21.6 weeks; P = .0002) than those with spontaneous preterm premature rupture of membranes. The perinatal survival rate was 91% in preg nancies complicated by preterm premature rupture of membranes after genetic amniocentesis compared with a rate of 9% in control subjects (P = .005). CONCLUSIONS: Pregnancies complicated by preterm premature rupture of membra nes after genetic amniocentesis result in significantly better perinatal ou tcomes compared with pregnancies complicated by spontaneous preterm prematu re rupture of membranes at a similar gestational age. Expectant management should be considered in such cases.