Association of amniotic fluid index with feto-maternal outcomes: a prospective observational study

Background: Amniotic fluid index (AFI) serves as a critical marker for foetal wellbeing. Abnormal AFI values such as oligohydramnios and polyhydramnios have been associated with adverse pregnancy outcomes. Objective was to assess the association between AFI and feto-maternal outcomes amongst pregnant women between 32 and 40 weeks of gestation. Methods: This prospective observational study was conducted at Holy Family Hospital, New Delhi, from July 2022 to March 2024. A total of 150 women with singleton pregnancies were evaluated and categorized into four groups based on AFI: oligohydramnios (<5 cm), borderline low (5.1-8 cm), normal (8.1-18 cm), and polyhydramnios (>18 cm). Clinical, intrapartum, and neonatal outcomes were analysed. Results: Of the 150 participants, 14% had oligohydramnios, 23.3% borderline low, 39.3% normal, and 23.3% polyhydramnios. Oligohydramnios was significantly associated with preterm birth (47.6%, p<0.0001), low birth weight (57.1%, p<0.0001), emergency caesarean (61.9%, p<0.0001), NICU admissions (71.4%, p=0.004), and low APGAR scores at 1 and 5 minutes (61.9%; p=0.001 and 23.8%; p=0.0009, respectively). Polyhydramnios was strongly associated with gestational diabetes mellitus (51.4%, p<0.0001) and increased birth weight. Conclusions: Abnormal AFI, particularly oligohydramnios, is significantly associated with adverse feto-maternal outcomes. Routine assessment of AFI should be emphasized in late pregnancy to enable timely intervention.