Polyhydramnios and associated maternal and fetal complications in singleton pregnancies.

During the 10-year period 1 January 1979 to 31 December 1988, polyhydramnios occurred in 537 patients with singleton pregnancies delivered at the Mercy Maternity Hospital. Associated maternal and fetal complications and the perinatal outcome of these pregnancies with polyhydramnios were analysed. In 248 of the 537 pregnancies (46%) in this group there were no maternal complications or fetal malformations and the perinatal mortality (PNM) rate was 2.4%. The PNM rate increased significantly to 13.1% when there was associated pre-eclampsia, 10% with gestational diabetes, and to 7.6% with miscellaneous complications. When polyhydramnios was associated with a fetal or placental malformation the PNM rate was 61.4%. The commonest malformations were central nervous system (31%), musculoskeletal (12%) and gastrointestinal system anomalies (10%). Placental chorioangioma occurred in two patients (0.4%) and both babies died. In women with low oestriol excretion (18% of the 455 tested) the PNM rate increased five times to 22.7%.