Amniotic fluid prostaglandins F2 alpha and E2, measured at artificial rupture of the membranes, predict the subsequent progress of labour.

Prostaglandin F2 alpha and E2 concentrations in the amniotic fluid and fetal membranes of 35 patients was analysed, in order to investigate differences in prostaglandin synthesis in parous and nulliparous women, and to find whether women who subsequently required oxytocin to accelerate labour, showed any difference in intrauterine prostaglandin concentrations. Significantly less PGF2 alpha was detected in the amniotic fluid of women who required oxytocin, and fetal membrane PGE2 was significantly lower in these women at delivery. Differences in PGE2 and PGF2 alpha in parous and nulliparous women were less marked. Amniotic fluid levels of PGF2 alpha at Artificial Rupture of the Membranes (ARM), and the ratio of PGF2 alpha/PGE2 at ARM, were prognostic for the subsequent progression of labour.