A comparison of plasma prostaglandin levels in term and preterm labour.

Peripheral plasma levels of 13,14-dihydro-15-keto-prostaglandin F (PGFM) were determined in women during pregnancy and in term and preterm labour. The PGFM concentrations at term were not significantly different from the levels between 26 and 34 weeks gestation. In both term and preterm labour there was a rise in PGFM levels with increasing cervical dilatation although the mean values tended to be lower during preterm labour. These findings may provide an explanation for the effectiveness of prostaglandin synthetase inhibitors in suppressing myometrial activity in preterm labour.