Abstract

PIP: This study determines the effect of prostaglandins (PGs) on fetal-placental hormone production or luteal steroidogenesis early in pregnancy by measuring plasma levels of unconjugated estrone, 17-beta estradiol, estriol, progesterone, 17-hydroxyprogesterone, human chorionic gonadotropin (HCG), and human chorionic somatomammotropin (HCS) in 7 healthy women aged 15-30 years receiving PGF2alpha for therapeutic abortion. The patients were 7-20 weeks pregnant and were all from the Clinical Research Unit of the Yale-New Haven Hospital. 5 patients participated in a dose-response tolerance study in which the drug was given over a 12-hour period at predetermined dose levels from 25-200 mcg/minute. The remaining 2 patients received 50 mcg for 12 consecutive hours, and 2 6-hour periods respectively. Heparinized blood samples were collected prior to the beginning of the infusion, at least hourly during the infusion, and also 24 hours after the beginning of the study. Transabdominal and transcervical catheters were used to monitor intrauterine pressures. A definite decline in estradiol levels (from 50-70% of initial levels) was observed during the PGF2alpha infusions. Plasma levels of unconjugated estriol were found to decline earlier and more markedly than the estradiol levels. 17-hydroxyprogesterone was undetectable in all but 1 patient who was 7 weeks pregnant. There were no significant changes in HCG levels in 4 patients until abortion and or curettage was performed. HCS levels gradually declined in 3 patients during the infusion process. This study shows that PGF2alpha does not exert a luteolytic effect in terminating pregnancy from 7-20 weeks gestation, confirming the study of Wiqvist et.al. Further study of the 1st few weeks of gestation should be done before ruling out the possibility of luteolysis in humans.