Unexplained polyhydramnios and perinatal outcomes

Abstract

SRIRAM C. PERNI, JENNIFER E. CHO, ROBIN B. KALISH, MLADEN PREDANIC, STEPHEN T. CHASEN, Weill Medical College of Cornell University, Obstetrics & Gynecology, New York, NY OBJECTIVE: The relationship between polyhydramnios and poor neonatal outcomes has been inconsistent in the literature. The aim of our study was to determine the correlation between unexplained polyhydramnios and adverse perinatal outcomes. STUDY DESIGN: Over a 6-year period, 363 singleton pregnancies with polyhydramnios were identified from our ultrasound database. Patients with pregnancies complicated by diabetes or known fetal anomalies were excluded. Patients with polyhydramnios, defined as an amniotic fluid index (AFI) greater than 20 centimeters (cm), were stratified into categories of mild (AFI 20-24 cm), moderate (AFI 25-29 cm), and severe (AFI >30 cm). Perinatal outcome data were retrieved frommedical records. Chi-square, Fisher’s exact, andMann-WhitneyU tests were used for statistical analysis where appropriate. A P value < 0.05 was considered statistically significant. RESULTS: 304 pregnanciesmet inclusion criteria. Polyhydramnios wasmild in 190 cases (62%), moderate in 84 cases (28%), and severe in 30 cases (10%). There was a trend towards higher rates of malpresentation (15.4% vs 5.5%, P = 0.056) and cesarean section (74.1% vs 55.8%, P = 0.052) in cases with severe polyhydramnios, compared to mild and moderate. There was no association with fetal gender, birth weight, gestational age at delivery, incidence of preeclampsia, or NICU admission between pregnancies with severe polyhydramnios and those with mild/moderate polyhydramnios. While no neurological abnormalities were detected in neonates from the mild or moderate polyhydramnios groups, 2 of 30 neonates (6.7%) from the severe polyhydramnios group were neurologically abnormal (P < 0.001). One neonate experienced intractable seizures, and the other had dysmorphic features. CONCLUSION: In singleton pregnancies not complicated by diabetes or known fetal anomalies, polyhydramnios is associated with favorable outcomes in most cases. Severe polyhydramnios may indicate fetal neurological dysfunction, even in the absence of any apparent fetal abnormalities.