Polyhydramnios is the presence of excessive amniotic fluid surrounding the unborn infant.

Amniotic fluid surrounds and cushions the infant throughout development. Decreased or excessive amounts of amniotic fluid may be associated with abnormalities in the fetus. Polyhydramnios may result from failure of the fetus to swallow and absorb amniotic fluid in normal amounts. This may occur as a result of gastrointestinal disorders, neurological problems, or a variety of other causes. Polyhydramnios may also be related to increased fluid production, as is the case with certain fetal lung disorders. Sometimes, no specific cause for polyhydramnios is found.

• esophageal atresia
• duodenal atresia
• anencephaly
• hydrops fetalis
• achondroplasia
• Beckwith-Wiedemann syndrome
• diaphragmatic hernia
• gastroschisis
• multifetal gestations (for example, twins or triplets)
• gestational diabetes