Borderline amniotic fluid index and perinatal outcomes in the uncomplicated term pregnancy

To determine perinatal outcomes in uncomplicated term pregnancies with a borderline amniotic fluid index (AFI).

A retrospective review was conducted of uncomplicated singleton pregnancies at term (>37 weeks). Borderline and normal AFI were defined as 5.1 ≤ AFI ≤ 8.0 cm and 8.1 ≤ AFI ≤ 24 cm, respectively. Adverse perinatal outcomes, cesarean delivery for non-reassuring fetal heart rate testing, meconium-stained amniotic fluid, a 5-min Apgar score of <7, admission to the neonatal intensive care unit (NICU), and whether the neonate was small for gestational age were compared between the borderline and normal AFI groups.

Borderline AFI was not significantly associated with cesarean delivery for non-reassuring fetal heart rate testing (p = 0.513), meconium-stained amniotic fluid (p = 0.641), admission to the NICU (p = 0.368), or a 5-min Apgar score of <7 (p = 1.00). However, the number of neonates who were small for gestational age (p = 0.021) and rates of induction of labor (p < 0.001) were significantly higher in the borderline group. Multiple logistic regression analysis showed that borderline AFI was not associated with cesarean delivery for non-reassuring fetal heart rate testing (odds ratio [OR] = 0.72, 95% confidence interval [CI] 0.27-1.91, p = 0.52).

In uncomplicated term pregnancies, a borderline AFI does not increase the risk of adverse perinatal outcomes.