This retrospective cohort study of 671 singleton term pregnancies (≥37 weeks, 2017–2024) compared the diagnostic accuracy of AFI (<5 cm) versus MVP (<2 cm) for predicting a composite adverse perinatal outcome (cesarean for nonreassuring fetal heart rate, 5-min Apgar <7, umbilical artery pH <7.10, or meconium-stained fluid requiring neonatal airway intervention within 30 min), with special attention to discordant classifications.
The composite outcome occurred in 18.5% of pregnancies (124/671); AFI flagged oligohydramnios more often than MVP (21.0% vs. 8.2%), with higher sensitivity (26.6% vs. 10.5%) but lower specificity (80.3% vs. 92.3%), and AFI-only oligohydramnios was not independently associated with worse outcomes (aOR 1.28, 95% CI 0.80–2.05).
Single tertiary center retrospective design limits generalizability; both methods showed poor overall discriminatory performance (sensitivity ≤27%); the cohort was managed under MVP-guided practice, which may have altered outcomes for AFI-only oligohydramnios cases.
AFI detects more oligohydramnios cases than MVP but does not improve identification of at-risk pregnancies, and AFI-only oligohydramnios did not independently predict adverse outcomes. Current guideline preference for MVP over AFI remains supported by this evidence.
