Evidence for a local control of prostaglandins within the pregnant human uterus.

Prostaglandin F (PGF) and 13, 14-dihydro-15-keto-PGF (PGFM) have been measured in amniotic fluid in late human pregnancy. The method used to obtain amniotic fluid greatly influenced the levels of prostaglandins: fluid obtained by vaginal amniotomy contained significantly higher levels of both PGF and PGFM than samples taken at amniocentesis, reflecting an increase in synthesis and/or release of prostaglandin rather than a decrease in the rate of metabolism. After 36 weeks gestation there was no increase in levels of either PGF or PGFM if samples obtained by amniotomy and amniocentesis were considered separately, although if such samples were considered together a significant increase could be obtained. The apparently rapid change in prostaglandin concentrations in amniotic fluid in response to amniotomy strongly supports a local control of these compounds within the pregnant uterus.