Amnioreduction.

Pregnancies complicated by hydramnios are at increased risk of both maternal and fetal complications. Since amniotic pressure is elevated in polyhydramnios, it has been suggested that the complications may be mediated by anomalies connected with amniotic pressure. The rationale behind amnioreduction is thus to restore normal amniotic pressure by draining a large amount of amniotic fluid volume in order to reduce maternal discomfort, improve uteroplacental perfusion, and prolong pregnancy by limiting the risk of preterm labour and rupture of the membranes.