Inhibition of prostaglandin E2 production in myometrial and amniotic cells in culture by human amniotic fluid. Loss of inhibition after intra-uterine fetal death

Termination of pregnancy in patients with previous cesarean section

OBJECTIVE

To evaluate the safety and efficacy of termination of pregnancy using mifepristone and misosprostol at more than 15 weeks' gestation in patients with uterine scar due to previous cesarean section.

MATERIALS AND METHODS

This retrospective study was conducted in a tertiary maternity ward between January 2000 and October 2004. A total of 252 women at more than 15 weeks' gestation underwent termination of pregnancy including 50 women with uterine scar due to previous cesarean section (Group 1) and 202 control patients (Group 2) without known uterine scar. Abortion was induced with mifepristone and a prostaglandin analogue. Women between 15 and 34 weeks' gestation received misoprostol intravaginally every 3 h at doses of 200 microg (Group 1) or 400 microg (Group 2). Women at more than 34 weeks' gestation received Prostin E2 vaginal gel. Main end points were hemorrhage, fever, retained placenta, occurrence of complications including uterine rupture and dehiscence, and final outcome.

RESULTS

A total of 13 (26%) patients in Group 1 and 79 (39.1%) in Group 2 were at more than 24 weeks' gestation. The abortion failure rate was 2% (1/50) in Group 1 and 0.5% (1/202) in Group 2 (p = .28). The median induction-to-delivery interval was 8.5 h (range, 3.0-114.2 h) for Group 1 and 9.0 h (range, 1.3-124.3 h) in Group 2 (p = .26). One case of uterine rupture and one case of dehiscence were observed, both in women in Group 1. The incidence of hemorrhage was not significantly different between Group 1 and Group 2 (2% vs. 0.9%, respectively, p = .56). The incidence of retained placenta was higher in the Group 1 (70% vs. 52.5%, respectively, p = .025).

CONCLUSION

In this retrospective series of women who underwent abortion at 15-35 weeks' gestation using mifepristone and a prostaglandin analogue for labor induction abortion, history of cesarean section was not associated with higher morbidity except risk of uterine rupture. However, dose and interval of misoprostol should be determined. A larger study is needed before drawing definitive conclusions about the safety of these regimens.

Extra-amniotic prostaglandin E2 for midtrimester termination of pregnancy in live fetuses vs. fetal demise

This study compared the course of midtrimester termination of pregnancies with fetal demise and those with a viable fetuses by extra-amniotic prostaglandin (PG) E(2). A total of 275 women who underwent second trimester abortion with extra-amniotic PGE2(2) were divided into two groups: 95 patients (35%) with fetal demise and 180 women (65%) with a live fetuses. Extra-amniotic PGE2(2) was administered in doses of 200 micro g every 2 h up to 20 doses. Bumm curettage was performed in the majority of the patients. We compared the duration and complication rate between the groups. The median induction to abortion interval was significantly shorter in the fetal demise group (13 vs. 21 h) than in the live fetus group. Mean gestational ages and complication rates were similar. Midtrimester termination of pregnancy with extra-amniotic PGE2(2) is a safe method with a low complication rate. In cases of pregnancy with fetal demise extra-amniotic PGE2(2) is associated with a significantly shorter induction to abortion interval than with a live fetus.

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.