Massive initial prostaglandin impact in postconceptional therapy

Abstract

The abortifacient effect of an initial PG F2α impact has been examined in 10 obstetrically normal first trimester pregnant patients. Sedated patients were given extraamniotically an average initial dose of 8.1±0.8mg PG F2α during a 10 minute instillation. Side effects occurred occasionally but were minimal. Uterine contracture developed rapidly reaching an average pressure of 83.2±11.3mm Hg in about 20 minutes, and then slightly declined with time. Superimposed on the contracture response were gradually increasing cyclic changes in intrauterine pressure which reached a magnitude of 129.8±12.2mm Hg by 10 hours after initial treatment. Initial therapy was augmented in some cases by an average of 4mg PG F2α; only 4 patients required oxytocin supportive therapy. The patients aborted in an average of 10.9±2.0 hours. Seven aborted completely, 2 left behind small placental residues and one retained the placenta during a period of 11.5 hours. An abortion score (AbS) of 92 was obtained in the study which is the highest in 6 consecutive studies using various methods of PG F2α administration. Plasma estradiol-17⨿ and progesterone levels decreased continuously during the instillation abortion time in the complete aborters, while the incomplete aborters showed lesser changes. It is concluded that massive intrauterine PG F2α injection is a more efficacious and acceptable form of postconceptional therapy than protracted treatment. Such therapy appears to convert the refractory uterus into a spontaneously active and pharmacologically reactive organ by inducing vasoconstriction, myometrical stretch, and feto-placental insufficiency.