Borderline amniotic fluid index as a predictor of adverse perinatal outcomes

Objectives: To determine whether the borderline amniotic fluid index (bAFI) at term in low risk pregnancies is associated with adverse perinatal outcome Method: A retrospective cohort study carried out over a period of 3 months. 303 uncomplicated pregnant women who delivered at term and who had amniotic fluid assessment in 4 days of delivery were recruited. An AFI of 5-10 cm was defined as borderline and an AFI of 10 cm- 24 cm normal. Intrapartum pathological cardiotocograph (CTG), meconium stained amniotic fluid (MSAF) at amniotomy or spontaneous rupture of membranes (SROM), instrumental vaginal delivery (IVD) or emergency caesarean delivery (CD) due to fetal distress, 5 min APGAR less than 7 and admission to the neonatal unit (NNU) were considered as the measures of adverse perinatal outcomes. Results: Eighty three (27.0%) of the 303 subjects had borderline AFI. Statistically significant differences were observed between the proportions of patients in the two groups with regard to MSAF at amniotomy, (18.1% vs. 17.7%, RR 1.02, 95% CI 1.23 to 1.76, p= 0.01) or SROM (48.2% Vs 60%, RR 0.80, 95% CI 1.2 to 2.1), AVD or emergency LSCS due to fetal distress (P=<0.001 and P=0.01 respectively). Intra partum pathological CTG (4.8% vs. 1.4%RR 3.42, 95% CI 0.56 to 2.67, P= 0.10), and less than 7 APGAR at 5 minute after delivery (2.4% vs. 0.5%, RR 4.8, 95% CI 0.67to 2.83, p= 0.05),) were not statistically significant. Proportion of babies admitted to NNU were significantly higher with borderline AFI compared to normal AFI (15.7% vs. 5.5%, RR 2.85, 95% CI 1.06 to 2.32, p= 0.01) Conclusions: Women with borderline AFV have a higher chance of their babies getting admission to the NNU immediately after delivery. Meconium stained amniotic fluid, non-reassuring CTG changes and interventions due to fetal distress, which were statistically significant, may contribute to above observation.