Transabdominal Amnioinfusion Treatment of Severe Oligohydramnios in Preterm Premature Rupture of Membranes at Less Than 26 Gestational Weeks

Preterm premature rupture of membranes (pPROM) in the second trimester is a prominent cause of maternal and fetal morbidity as well as fetal death. More than two thirds of affected pregnancies end within a week after pPROM. Among the consequences of persistent oligohydramnios are pulmonary hypoplasia, skeletal deformities, cord compression, chorioamnionitis, and endometritis. The investigators examined the efficacy of transabdominal amnioinfusion in 71 patients having pPROM and severe oligohydramnios at less than 26 weeks gestational age. Serial amnioinfusions of saline were given to 37 women, whereas the remaining 34 were managed expectantly. Amnioinfusion was first given at least 7 days after pPROM and was repeated at weekly intervals if oligohydramnios persisted as evidenced by an amniotic fluid index (AFI) less than 30 mm. Saline was infused into the amniotic cavity until the AFI exceeded 100. The 37 actively treated women received a total of 147 amnioinfusions. Four procedures were unsuccessful and had to be repeated. In nearly half of patients, some infused fluid was lost during or within 6 hours after the procedure. No infant had external lesions attributable to amnioinfusion. Complications in the first 24 hours included 2 cases each of cord prolapse and abruptio placentae and 1 case of immediate labor. The latency period to delivery and gestational week of delivery were higher in treated than in control women, as were neonatal weight and the chance of intrauterine fetal survival (65% vs. 32%). Infectious complications were not more frequent in women receiving amnioinfusion. Five of 8 deaths from pulmonary hypoplasia were in the amnioinfusion group, as were 7 of 8 severely premature infants. Two infants in the study group died of severe bronchopulmonary dysplasia. These findings strongly suggest that amnioinfusion is a low-risk procedure that could lengthen the fetal intrauterine stay and improve survival in cases of pPROM with severe oligohydramnios.