Intrauterine growth restriction and oligohydramnios among high-risk patients

Area of Science:

• Obstetrics and Gynecology
• Fetal Medicine
• Perinatology

Background:

• Intrauterine growth restriction (IUGR) and small for gestational age (SGA) are common concerns in high-risk pregnancies.
• Oligohydramnios, defined as an amniotic fluid index (AFI) < 5.0 cm, is often monitored in these cases.
• The predictive value of oligohydramnios for adverse peripartum outcomes requires further clarification.

Purpose of the Study:

• To determine the prevalence of oligohydramnios in fetuses with IUGR and newborns with SGA.
• To assess the predictive accuracy of AFI < or = 5.0 cm versus > 5.0 cm for adverse peripartum outcomes in fetuses with IUGR.

Main Methods:

• Retrospective review of high-risk pregnancies with reliable gestational age and weekly biophysical profile (BPP) assessments.
• Calculation of prevalence, 95% confidence intervals (CIs), and likelihood ratios (LRs) for adverse outcomes.
• Analysis based on Evidence-Based Medicine Working Group guidelines.

Main Results:

• Among 1859 singletons, IUGR was suspected in 22% and SGA in 28%.
• Prevalence of oligohydramnios was 6% in both IUGR fetuses and SGA newborns (95% CI, 4% to 8%).
• Oligohydramnios showed limited predictive accuracy for cesarean delivery (LR 2.0), SGA (LR 1.9), and NICU admission (LR 1.4) in IUGR fetuses. Over 90% of IUGR/SGA cases had AFI > 5.0 cm.

Conclusions:

• Oligohydramnios occurs in approximately 6% of fetuses with IUGR and SGA newborns.
• A low amniotic fluid index (< 5.0 cm) is a poor predictor of adverse peripartum complications in fetuses with IUGR.
• The majority of high-risk pregnancies (IUGR/SGA) do not present with oligohydramnios.