AMNIOINFUSION FOR PREVENTION OF PULMONARY HYPOPLASIA IN 2ND-TRIMESTERRUPTURE OF MEMBRANES

We conducted a study to evaluate the feasibility and benefits of trans abdominal amnioinfusion in preterm premature rupture of membranes with persistent oligohydramnios for the prevention of pulmonary hypoplasia . To this purpose, we designed a cohort study in which the pregnancy o utcome of women with rupture of membranes at less than or equal to 25 weeks and persistent (greater than or equal to 4 days) oligohydramnios managed with serial amnioinfusions (n=18) was compared with that of a historic cohort group (controls) with similar characteristics but man aged expectantly (n=16). Pulmonary hypoplasia was diagnosed at birth i n the presence of strict radiological and pathological criteria. No am nioinfusion-related complications occurred. The prevalence of pulmonar y hypoplasia was significantly lower among the amnioinfused cases comp ared with the controls (46% [6 of 13]vs 86% [12 of 14], odds ratio [OR ]=0.4, 95% confidence interval [CI]0.2-0.9), despite a lower gestation al age at rupture of membranes in the treated group. Within the group undergoing amnioinfusions, those in which the infused solution was rap idly lost had a higher rate of pulmonary hypoplasia compared with thos e in which amnioinfusion alleviated oligohydramnios for >48 hours (con sidered successful) (0 of 4 vs. 6 of 9, OR=2.3, 95% CI1-5.5). Cases of successful amnioinfusion had a longer interval between membrane ruptu re and appearance of oligohydramnios than those in which the procedure failed to correct oligohydramnios, even though both groups had simila r gestational age at appearance of oligohydramnios. This suggests that the rate of loss of amniotic fluid after membrane rupture may predict the rate of loss of the infused solution, and therefore identify a su bset of patients who may benefit from the procedure.