[Cervical preinduction and oligoamnios]

Twelve percent of women with 41 weeks of gestation and more had oligoamnios. Physiopathological mechanism of this disease still is under discussion.

To evaluate perinatal result of patients with more than 41 weeks of gestation oligoamnios-preinduced.

Analytic-observational and retrospective cohorts study. Patients with more than 41 weeks of gestation, oligoamnios-preinduced, were included. All patients received dinoprostone and had a Bishop score lower than seven. Amniotic fluid index of five or lower suggests diagnosis of oligoamnios. Preinduction indication, characteristics of intrapartum fetal monitoring, umbilical artery pH, Apgar score, neonatal weight, and admission in a neonatal unit were the variables analyzed.

Among the 96 patients, 28 (29.2%) constituted the exposed cohort and 68 (70.8%) the non-exposed one. Both groups were homogeneous in maternal age, parity and initial Bishop score. There weren't significant differences for way of delivery, cesarean section indications, meconium-stained amniotic fluid and umbilical cord pathology. Frequency of bradycardia was significantly higher in oligoamnios group (14.3 vs 1.5%), as well as Apgar score at first (mean of 8.86 vs 8.38) and fifth birth minute (mean of 9.89 vs 9.69). Fetal weight was significantly lower (3,298 vs 3,546 g) in oligoamnios group. Admission in neonatal unit was higher in the non-exposed cohort (1.47%).

Newborns of patients with oligoamnios had a better Apgar score, lower fetal weight and higher frequency of intrapartum bradycardia (without neonatal damage). A further study may offer new conclusions.