Serial amnioinfusions prevent fetal pulmonary hypoplasia in a large animal model of oligohydramnios

Background/PurposeSevere neonatal pulmonary hypoplasia incurs mortality rates approaching 71% to 95%. We sought to determine the utility of serial amnioinfusions through a subcutaneously implanted intraamniotic catheter to prevent pulmonary hypoplasia in fetal obstructive uropathy.MethodsFetal lambs (n = 32) were divided into 3 groups. Group I (n = 12) underwent a sham operation, group II (n = 15) underwent a complete urinary tract obstruction via ligation of the urachus and urethra with a subcutaneous tunneled intraamniotic port-a-cath without amnioinfusions, and group III (n = 5) underwent a creation of a complete urinary tract obstruction with a port-a-cath as described in group II with serial amnioinfusions. Lung tissue was analyzed by lung volume to body weight ratios and stereology. Statistical analysis was performed by analysis of variance and Bonferroni comparisons (P < .05).ResultsObstructed fetuses grossly had smaller lungs than treated and control animals. Lung volume to body weight ratios were statistically significant between groups. Airspace fractions were comparable between groups I and III (average = 0.53 and 0.55, respectively), although both were significantly greater than group II (average = 0.48) (P = .049).ConclusionsSerial amnioinfusions through an intraamniotic port-a-cath prevented pulmonary hypoplasia in an ovine model of complete obstructive uropathy. The use of an easily accessible device for amnioinfusions may be a viable option to treat oligohydramnios.