Perinatal Outcome in Patients with Isolated Oligohydramnios at Term: AProspective Study

Objective: To evaluate the perinatal outcome in patients with isolated oligohydramnios. Design: A prospective study. Sample: 146 patients had isolated oligohydramnios. These were compared with those having AFI>5 cm (n=500). Methods: A prospective study was conducted from November 2012 to November 2014. Patients were divided into two groups (AFI>50 mm and ≤ 50 mm). The study inclusion criteria were women with singleton pregnancy at 36-42 weeks gestational age (GA) and women sure of the gestational age. Main outcome measures: Abnormal non-stress test, obstetric intervention for fetal distress, Apgar score, meconium stained liquor and NICU admission. Results: The two groups were similar with regard to maternal age, parity and mean gestational age. Isolated oligohydramnios was associated with higher rate of induction of labour (68.49% vs. 21.8%, p<0.001), nonreassuring fetal heart rate (45.20% vs. 13.2%, p<0.001), cesarean section for fetal distress (51.61% vs. 28.47%, p<0.001), meconium stained amniotic fluid (32.2% vs. 21.6%, p=0.008). However, there was no statistically significant difference between the two groups in terms of Apgar score at 1 min, NICU admissions and stillbirths. Conclusion: Isolated oligohydramnios is associated with increased risk of obstetric interventions particularly due to fetal distress. Nonetheless, fetal distress due to oligohydramnios did not lead to increased risk for low Apgar, NICU admissions, stillbirths. This may be reflective of aggressive intrapartum management that these patients received.