Effects of intracervical prostaglandin E2 on fetal heart rate and uterine activity patterns in the presence of oligohydramnios.

OBJECTIVE

Our purpose was to compare fetal heart rate patterns and uterine activity before and after preinduction prostaglandin E2 administration in the presence or absence of oligohydramnios.

STUDY

DESIGN

In a retrospective case-controlled review we examined cases in which prostaglandin E2 (Prepidil) was inserted intracervically for gravid women requiring an induction of labor in the presence of either oligohydramnios (amniotic fluid index < or = 5.0) or adequate fluid (amniotic fluid index 5.1 to 23.9). Uterine activity and fetal heart rate tracings that were begun 1 hour before and continued for 6 hours after dosing were interpreted without knowledge of amniotic fluid volume.

RESULTS

Cases in the oligohydramnios (n = 51) and adequate fluid (n = 49) groups were the same for maternal age, race, parity, gestational age, and predose Bishop score. Patients with oligohydramnios had more high-amplitude contractions in the first hour after dosing (9.0 +/- 1.2 vs 6.1 +/- 0.9, p < 0.05), but there were no significant differences in the frequency or duration of contractions during the subsequent 5 hours. Uterine hyperstimulation was not seen, and there were no differences in the frequency of variable or late fetal heart rate decelerations.

CONCLUSION

For pregnancies undergoing preinduction cervical ripening with intracervical prostaglandin E2, the presence of oligohydramnios was not associated with a greater risk of fetal heart rate decelerations, although contractions were more common during the first hour after dosing.