Amnioreduction was developed in order to treat polyhydramnios (excess amniotic fluid), intially to relieve maternal discomfort and subsequently to prolong gestation as this outcome became apparent.

It involves the aspiration of large quantities of amniotic fluid from a pregnancy complicated by either overproduction of, or obstructed circulation of amniotic fluid where the fetus is still salvageable.

This often occurs in situations where there is twin to twin transfusion or gastrointestinal tract obstruction.

By preventing preterm labour, the outcome of pregnancies can be improved by this procedure.