ABSTRACT
We conducted a study to evaluate the feasibility and benefits of transabdominal amnioinfusion
in preterm premature rupture of membranes with persistent oligohy-dramnios for the
prevention of pulmonary hypoplasia. To this purpose, we designed a cohort study in
which the pregnancy outcome of women with rupture of membranes at ≤ 25 weeks and persistent
(≥ 4 days) oligohydramnios managed with serial am-nioinfusions (n = 18) was compared with that of a historic cohort group (controls) with similar characteristics
but managed expectantly (n = 16). Pulmonary hypoplasia was diagnosed at birth in the presence of strict radiological
and pathological criteria. No amnioinfusion-related complications occurred. The prevalence
of pulmonary hypoplasia was significantly lower among the amnioinfused cases compared
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 gestational age at rupture of membranes in
the treated group. Within the group undergoing amnioinfusions, those in which the
infused solution was rapidly lost had a higher rate of pulmonary hypoplasia compared
with those in which amnioinfusion alleviated oligohydramnios for >48 hours (considered
successful) (0 of 4 vs. 6 of 9, OR = 2.3, 95% Cl 1-5.5). Cases of successful amnioinfusion
had a longer interval between membrane rupture and appearance of oligohydramnios than
those in which the procedure failed to correct oligohydramnios, even though both groups
had similar 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 subset of patients who may benefit
from the procedure.
Keywords
Fetal membranes - premature rupture - pulmonary hypoplasia - amnioinfusion - oligohydramnios
