Effect of amniotic fluid upon prostaglandin E2 and I2 production by cultured human myometrial cells.

OBJECTIVE

Our goal was to study the effect of amniotic fluid obtained at 16 and 39 weeks of gestation in normal human pregnancies upon prostaglandin production by human myometrial cells in culture.

STUDY

DESIGN

Amniotic fluid, sampled either at 16 weeks, during amniocentesis, or at 39 weeks, during caesarean section before labor, was fractionated by molecular-weight and then incubated with human myometrial cells in culture. We then used radioimmunoassay to measure PGE(2) and PGI(2) production.

RESULTS

The "3-30 kDa" fraction of amniotic fluid sampled at 16 weeks significantly inhibited PGE(2) and PGI(2) production by human myometrial cells. When amniotic fluid was sampled at 39 weeks, it stimulated both PGE(2) and PGI(2) production, and the ">30 kDa" fraction increased levels of PGE(2) considerably more than of PGI(2) (420.0+/-88.0 ng/10(6)cells versus 188.2+/-21.4 ng/10(6)cells, P<0.001).

CONCLUSION

Amniotic fluid contains substances whose effects in cultured myometrial cells vary according to gestational age and type of prostaglandin. These data suggest that the fetus plays a role in the regulation of myometrial activity during pregnancy.