Polyhydramnios as a predictor of adverse pregnancy outcomes.

OBJECTIVES This study aimed to ascertain the frequency of polyhydramnios in singleton pregnancies, to determine the associated risk factors, and assess the adverse maternal and perinatal outcomes. METHODS A retrospective cohort study of all singleton pregnancies complicated with polyhydramnios after 28 weeks of gestation was carried out in Nizwa Hospital's Obstetrics & Gynecology Department, Oman, from January 2002 to December 2007. Of 25,979 pregnant women reviewed, 477 were found to have polyhydramnios. The control group consisted of 900 pregnant women. Cases of polyhydramnios were diagnosed as mild, moderate, or severe based on their highest amniotic fluid index. Cases were compared with controls in terms of demographic data; prevalence of diabetes, macrosomia, or Caesarean deliveries; frequency of fetal anomalies, and perinatal mortality rate. RESULTS Polyhydramnios was diagnosed in 1.8% of pregnancies. It was mild in 382 (80%), moderate in 84 (17.6%), and severe in 12 (2.4%). A total of 72 (15.3 %) cases of polyhydramnios were complicated by diabetes (gestational or established diabetes mellitus) as compared to 10% of the control group and 39 (8.1%) neonates had congenital anomalies. Polyhydramnios was associated with advanced maternal age; 58 (12.2%) of subjects were over 40 years old. The perinatal mortality rate with polyhydramnios was 42 per 1,000 births compared to 14 per 1000 births in the control group. CONCLUSION These data demonstrate that polyhydramnios is associated with an increased risk of adverse perinatal outcomes, and there is a significant positive relation with maternal age, diabetes, fetal anomalies, and fetal macrosomia.