Polyhydramnios

Pathological excess of amniotic fluid within the amniotic cavity during pregnancy, typically diagnosed sonographically by an elevated amniotic fluid index or deepest vertical pocket measurement.

Causes

• Maternal diabetes mellitus causing fetal polyuria

• Fetal structural abnormalities

  • Esophageal atresia

  • Duodenal atresia

  • Other gastrointestinal obstructions impairing fetal swallowing

  • Central nervous system disorders causing impaired swallowing

  • Fetal cardiac disorders

  • Craniofacial malformations interfering with swallowing

• Genetic and chromosomal causes

  • Trisomy 13/18/21

  • Genetic syndromes associated with fetal anomalies

• Twin-to-twin transfusion syndrome

• Hematologic causes

  • Fetal anemia

  • Rh blood group incompatibility (hemolytic disease of the fetus)

• Congenital infections

  • Cytomegalovirus (CMV)

  • Toxoplasmosis

  • Parvovirus B19