Prostaglandin E production by amniotic cells in relation to term and preterm labour

The rate of prostaglandin E (PGE) production was measured in collagenase-dispersed amniotic cells obtained from 14 women after spontaneous labour at term--seven after spontaneous preterm labour, nine after delivery by elective caesarean section at term and six after induction of labour at term. Cells were incubated with and without arachidonic acid and PGE was estimated by specific radioimmunoassay. Basal PGE output (pmol/10(6) cells per 3 h) was highest in the spontaneous labour group, 27.5 (SEM 5.5) and lowest in the preterm labour group, 4 (SEM 1.2) (P less than 0.001). Values in the elective section and induction groups were 13.6 (SEM 2.7) and 10 (SEM 3.1), respectively; these values were significantly higher than in the preterm labour group and the values after induction were significantly lower than after spontaneous labour. Addition of arachidonic acid resulted in a significant increase in PGE output in all groups, but the values after preterm labour remained significantly lower than those of any group at term. These data indicate that towards term there is a maturation in the PG synthetase activity of the amnion and that PGE output in this tissue is increased in spontaneous labour.