Indomethacin therapy and fetal urine production in twins with polyhydramnios.

Indomethacin has been used in twins with polyhydramnios to decrease amniotic fluid volume. Under therapy, a marked reduction of both fetuses' urine production has been demonstrated within 24 hours concomitant with maternal symptomatic relief. Discontinuation of therapy was associated with a rapid increase in fetal urine production. The clinical observation indicates that the benefit of indomethacin in prolonging such pregnancies is most probably the result of relief of polyhydramnios through decreased fetal urine production.