THE PLACENTAL AND FETAL RESPONSE TO THE INTRA‐AMNIOTIC INJECTION OF PROSTAGLANDIN F_2α IN MIDTRIMESTER ABORTIONS

Abstract

Summary The placental and fetal response to the intra‐amniotic injection of prostaglandin F2α (PGF2α) for midtrimester abortions was evaluated. Maternal blood samples for radioimmunological determinations of serum progesterone, human placental lactogen (HPL) and alpha‐fetoprotein (AFP) were taken before and serially until 24 hours after the injection of 40 mg (nine patients) or 75 mg (seven patients) of PGF2α. Fetal heart action was monitored ultrasonically during the same period. The average induction‐abortion interval was 22.6 hours and was independent of the dose of PGF2α used. The mean progesterone and HPL levels showed a significant fall half an hour after PGF2α. The constant decreases began only at 5 hours and later. The mean AFP levels increased rapidly after 5 hours following injection of PGF2α. The fetal heart stopped at a mean of 10.4 hours (range 0.5 to 25 hours) after the injection of PGF2α. No relationship between the time of fetal death or rises in AFP and the induction‐abortion interval could be detected. The primary hormonal response of the placenta and the efficacy of exogenous PGF2α were not related, indicating the possibility that the abortifacient property of PGF2α is not related to its primary effect on placental hormone synthesis or release.

Expression and Localization of the Contractile Prostaglandin F Receptor in Pregnant Rat Myometrium in Late Gestation, Labor, and Postpartum1

“…Peripheral progesterone concentrations are high during gestation and decline before parturition in the rat; however, estrogen concentrations are low throughout gestation and rise just before parturition [21]. These changes in steroid hormones are reflected by changes in concentrations of rat myometrial nuclear estrogen and progesterone receptors [43].…”

“…Measurements of PGF 2␣ in the uterine vein of pregnant rats showed that the concentrations increased gradually from Day 15, with the highest concentrations around delivery (Day 22) [19,20]. Exogenous PGF 2␣ has been shown to induce labor [21], and administration of the cyclooxygenase inhibitor indomethacin inhibits uterine contractions and labor [22]. Interestingly, in FP knockout mice, spontaneous labor did not commence even 1 wk after term due to failure of PGF 2␣ -induced corpus luteum regression [23].…”

Preterm Labour: An Overview of Current and Emerging Therapeutics

“…Such a mechanism may explain the sustained release of prostaglandins in uterine tissue promoting labour. PGF 2α contracts the myometrium in vitro and in vivo [334]. Decidua produces more PGF 2α before labour than during labour [335].…”

Erythroid colony formation from human fetal liver.

“…Basch (4) and Shchory and Weatherall (5) have reported that, in cultures of liver from fetuses delivered by hysterotomy, hemoglobin synthesis markedly declined or ceased after [7][8] days.…”

“…With abortion by either of these methods, the fetus dies in utero (8) and is not usually expelled for 6-48 hr. Reports of successful culture of tissues from abortuses induced by hypertonic solution or prostaglandin have been limited to skin fibroblasts (9,10).…”