NEONATAL PULMONARY MECHANICS AND OXYGENATION AFTER PROPHYLACTIC AMNIOINFUSION IN LABOR - A RANDOMIZED CLINICAL-TRIAL

Objective. Amnioinfusion has been reported to improve the perinatal ou tcome of pregnancies complicated by decreased amniotic fluid volume, b ut detailed information on its possible adverse effects on neonatal pu lmonary mechanics and oxygenation is not available. Study design. We e valuated 42 infants with birth weights of 2600 to 4320 g and gestation al ages of 36 to 44 weeks, who were born to mothers enrolled in a pros pective, randomized trial of amnioinfusion for oligohydramnios in labo r. Maternal entry criteria were gestational age 36 weeks or older, est imated fetal weight more than 2500 g, oligohydramnios defined as an am niotic fluid index of 5 cm or less, and a normal fetal heart rate patt ern. Evaluation of pulmonary mechanics and oxygen saturation (SaO(2)) was done with the infants breathing room air between birth and day 3 o f life. Transpulmonary pressure, flow, and tidal volume were recorded simultaneously, and pulmonary resistance and lung compliance were calc ulated. SaO(2) was measured for 30 minutes with the Nellcor N-200 oxim eter and IBM computer oximetry software. Results. Evaluation of the da ta revealed no significant difference between the two groups for tidal volume, lung compliance, pulmonary resistance, or work of breathing. There were no differences between the two groups in the number of desa turation episodes or in percent of desaturations to less than 90%, 85% , of 80% SaO(2). Conclusion. Prior studies have shown amnioinfusion to improve perinatal outcome. Our findings demonstrate that amnioinfusio n for oligohydramnios in labor does not adversely affect neonatal pulm onary mechanics or oxygenation.