Effect of betamethasone on analysis of amniotic fluid in the rhesus-sensitized pregnancy.

Betamethasone was administered to six rhesus-sensitized pregnant women carrying seven fetuses in an attempt to accelerate fetal pulmonary maturation. A reduction in optical density of amniotic fluid at 450 mmu was observed in all cases following steroid therapy; however, only minimal changes were noted in the lecithin-sphingomyelin ratio. The implications of these findings for the management of rhesus-sensitized pregnancies are discussed.