IDIOPATHIC POLYHYDRAMNIOS - ASSOCIATION WITH FETAL MACROSOMIA

PURPOSE: To determine the relationship between idiopathic polyhydramnios and fetal macrosomia in the absence of maternal diabetes. MATERIALS RND METHODS: Idiopathic polyhydramnios was studied with ultrasound (US) in 99 consecutive normal fetuses of nondiabetic women. Birth weights and estimated fetal weights were compared with those of postnatal and prenatal control groups, respectively. RESULTS: The mean birth weight for the study (polyhydramnios) group was 3,771 g +/- 572 (standard deviation) compared with 3,476 g +/- 444 for the postnatal control group (P <.001). Birth weights in the 90th percentile or greater occurred in 28.2% of the study group versus 9.3% of the postnatal control group (P <.001) with a relative risk of 3.0 and a 95% confidence interval of 1.9, 4.9. The mean percentile of estimated fetal weight obtained with US was also significantly greater for the study group (79.3 +/- 23.7) than for the prenatal control group (51.5 +/- 32.7) (P <.001). CONCLUSION: Idiopathic polyhydramnios is associated with large-forgestational-age fetuses and macrosomia independent of maternal diabetes.