Effect of elective induction of labor with prostaglandins F2alpha and E2 and oxytocin on uterine contraction and relaxation.

Prostaglandins F2alpha and E2 and oxytocin were used to induce labor in 101 patients at risks. The data show that the three drugs are efficient labor inducers. The success rate of induction is the highest in primiparous patients receiving oral prostaglandin E2. Uterine contractility patterns and base line are similar with all drugs. The relaxation phase of the uterine contraction is skewed consistently in each investigated labor. This suggests an unequal relaxation time for the uterine fibers. It is concluded that prostaglandins E2 and F2alpha and oxytocin are safe drugs for induction of labor if monitoring is used in order to avoid an overdose of the medication. The three drugs must be synergistic because of their identical action on the uterine muscle.