F PROSTAGLANDINS IN AMNIOTIC FLUID DURING PREGNANCY AND LABOUR

Abstract

Summary Concentrations of prostaglandin F (PGF) have been measured, by radioimmunoassay, in samples of amniotic fluid from patients with normal pregnancies. Amniotic fluid contained significantly more PGF at term prior to the onset of labour than in mid‐pregnancy (p<0.01), and significantly more during spontaneous labour, at a cervical dilatation of three cm. or less, than before the onset of labour (p<0.001). During spontaneous labour PGF concentrations in amniotic fluid varied between 1.2 and 39.5 ng. per ml., and increased significantly with advancing cervical dilatation (p<0.001). Levels of PGF in the early first stage of oxytocin‐induced labour were higher than the levels obtained before the onset of labour (p<0.025), but lower than those obtained during spontaneous labour (p<0.05). It was demonstrated, by gas liquid chromatography with electron‐capture detection, that PGF 2α is the major PGF component in amniotic fluid during labour.