Prophylactic amnioinfusion for oligohydramnios: a reevaluation.

OBJECTIVE

To compare the effects of prophylactic amnioinfusion to standard care plus indicated therapeutic amnioinfusion (for variable decelerations) in term patients with oligohydramnios.

METHODS

One hundred sixteen term gestations with oligohydramnios (amniotic fluid index less than 5.0 cm) were randomly assigned to receive prophylactic saline amnioinfusion (600-mL bolus followed by 3 mL/minute) or standard obstetric care (control). Control patients who subsequently developed moderate or severe variable decelerations received therapeutic amnioinfusion.

RESULTS

There was no significant difference in overall cesarean delivery (21 versus 17%; P = .68), cesarean delivery for fetal distress (7 versus 10%; P = .83), or umbilical gas values between the prophylactic amnioinfusion group (N = 56) and control group (N = 60), respectively. The rate of intrapartum fever was significantly increased among the prophylactic amnioinfusion patients (23 versus 7%; P = .02), although the duration of intrauterine monitoring (8.8 versus 6.5 hours; P = .06) and time from ruptured membranes to delivery (12.3 versus 14.3 hours; P = .51) were not different. Only 22% of the controls developed moderate or severe variable decelerations in the first stage of labor and received therapeutic amnioinfusion. Thus, in approximately four of five term patients with oligohydramnios, neither prophylactic nor therapeutic amnioinfusion would be indicated.

CONCLUSIONS

Compared to indicated amnioinfusion, prophylactic amnioinfusion did not improve perinatal outcome. Amnioinfusion should be reserved for term laboring patients with variable fetal heart rate decelerations, rather than all patients with oligohydramnios.