Perinatal Outcome and Congenital Anomalies in Polyhydramnios –A Prospective Study

Abstract

Background: The amniotic fluid that envelops the fetus acts as a protective shroud. Fetal well-being is reflected by the amniotic fluid index. When the amniotic fluid index exceeds 25cms, it is called polyhydramnios and is associated with increased incidence of congenital malformations and perinatal mortality. Objectives: To estimate the incidence of congenital malformations and to study the perinatal outcome in polyhydramnios. Study Design: Prospective study. Setting: Neonatal intensive care unit and the maternity wards of Father Muller Medical College Hospital, Mangalore. Study period was 2 years. Methods: Amniotic fluid index was measured by ultrasound, 29 cases of polyhydramnios identified were evaluated and followed up. Congenital malformations were observed both by ante natal and post natal ultrasounds, other relevant investigations were also done when necessary. The perinatal outcome in terms of congenital anomalies, fetal distress and mortality were recorded. Results: 29 cases of Polyhdramnios were detected. Congenital malformations were identified in seven neonates (24.1%). Diaphragmatic hernia and hydrops fetalis were the most common congenital malformations observed. Nine neonatal deaths were documented (31%). Six cases of fetal distress were observed (19%). Incidence of congenital malformations and mortality increased significantly when the amniotic fluid index was above 30cms. Conclusion(s): There was a significant risk of congenital malformations, neonatal mortality and fetal distress in polyhydramnios, these risks rose exponentially with a further rise in amniotic fluid index over 30cms.