Serum levels of oestradiol and progesterone during administration of prostaglandin F2alpha for induction of abortion and labour.

Prostaglandin F2alpha was used to induce abortion or labour in 84 women between the 11th and 44th weeks of pregnancy. Three different routes of administration were used, intravenous, extra-amniotic, and intra-amniotic. The extra-amniotic infusion of prostaglandin F2alpha produced a faster response than the other two routes. Less than one-third of the dose used in the intra-amniotic group was required in the extra-amniotic group for a complete evacuation of the uterus. Vomiting and diarrhoea occurred in 40% of the women in the intra- and extra-amniotic group, while the frequency was 88% in the intravenous group. Serum levels of progesterone and oestradiol decreased in accordance with the pattern found during spontaneous deliveries. The effect of prostaglandin F2alpha on the myometrium does not appear to be mediated via changes in the blood levels of progesterone or oestradiol.