Low Amniotic Fluid Index as a Predictor of Adverse Perinatal Outcome – An Indian Perspective

Background: Oligohydramnios has increased incidence of meconium stained liquor, abnormal FHR tracing, low Apgar score, low birth weight, admission to NICU, birth asphyxia and cesarean section for fetal distress. Objective: To compare the perinatal outcome in women with singleton term pregnancies having amniotic fluid index (AFI) < 5cm to those having AFI between 6 to 20 cm. Material and methods: It is a prospective comparative study which included a total of 100 women with singleton term pregnancy with cephalic presentation, divided into two groups of 50 each. Women in Group 1 had amniotic fluid index <5 cm and in Group 2, had AFI from 6-20 cm. Primary outcome measures were fetal distress, meconium stained amniotic fluid, Apgar score less than seven at five minutes and low birth weight. Secondary outcome measures were caesarean section, neonatal complications and admission in NICU. Results: An AFI <5 cm was associated with significant high rate of induction of labor (p<0.001), caesarean section (p=0.04) and fetal distress (p<0.05). Meconium-stained liquor (p=0.76), Apgar score less than seven at 5 minutes (p=0.307), low birth weight (p=0.130) or NICU admission (p=1) were comparable in the two groups. Conclusion: Low AFI (<5cm) at term is associated with significantly high rate of intrapartum fetal distress and caesarean section, though the neonatal outcome is not affected by the AFI levels.