Objective: To analyze the utility of prophylactic amnioinfusion in term pregnancies with PROM and a low amniotic fluid index during labor induction.
Method: Forty-two women with amnioinfusion and 42 in a control group with amniotic fluid index (AFI) below 10 cm when admitted to labor induction were studied. All patients had electronic fetal heart rate and intrauterine pressure continuous monitoring. Amnioinfusion of normal saline (37 degrees C) was realized in the study group, using a continuous perfusion pump at 600 ml/h for 1 h, after which the AFI was again recorded; if this was < 15, the perfusion was continued at 180 ml/h until full cervical dilatation was achieved or until uterine baseline activity reached 20 mm Hg. The control group received identical obstetric care except in respect of amnioinfusion.
Result: Both groups were similar in age, primiparity, gestational age, initial AFI, interval from rupture of membranes until delivery and length of labor. The amnioinfusion of 600 ml in 1 h significantly increased the AFI (an increase of 7.2 +/- 3.9 vs. a decrease of 1.1 +/- 1.6, P < 0.01). In the amnioinfusion group, there was a significantly lower rate of cesarean deliveries (0 vs. 6, P < 0.05) and a better mean umbilical arterial pH at delivery (7.24 +/- 0.07 vs. 7.21 +/- 0.08, P < 0.05). No differences were observed in maternal or neonatal hospitalization days or infectious morbidity.
Conclusion: It is concluded that prophylactic amnioinfusion improves neonatal metabolic state when used in labor induction of term pregnancies with PROM and a low amniotic fluid index.