Clinical obstetric use of arachidonic acid metabolites and potential adverse effects.

Abstract

HE HISTORY of prostaglandins, their biochemistry, physiology, and clinical uses are inextricably intertwined with the history and practice of obstetrics and gynecology. A New York City obstetrician-gynecologist, Raphael Kurzrok, found that when he tried to treat infertility with intrauterine insemination, the semen was promptly expelled, while saline was not. In 1930, with Charles Leib, he reported’ that semen contained a factor that could stimulate uterine strips to contract or relax in vitro. These factors were physiologically characterized by Goldblatt* and von Euler,3 who coined the term prostaglandin. Bergstrom and Sjovall isolated and chemically characterized the first prostaglandin, PGF, in 1957.4 In the fifty years since Kurzrok and Leib’s observations, there has been an explosion of knowledge about the importance of prostaglandins as regulators of many physiologic processes, and their biochemistry and metabolism are much better understood. It is in reproductive medicine that the prostaglandins, especially those of the E and F series, have proven most useful to date as therapeutic agents. The female reproductive cycle from ovulation to puerperium offers perspectives for current and proposed clinical uses of prostaglandins. Prostaglandins are used to regulate ovulation in livestock,5 and can be used as postcoital contraceptives in humans. In pregnancy, prostaglandins have been shown to be potent abortifacients, allowing termination of pregnancy in any trimester. They are also useful as pharmacologic adjuncts to provide cervical softening and dilatation before surgical evacuation of the uterus. Later in pregnancy, when the induction of labor for specific maternal or fetal indications can be a vexing clinical problem, prostaglandins are a safe and reliable pharmacologic means of achieving vaginal delivery, either alone or in combination with oxytocin. Finally, prostaglandins are the most effective pharmacologic treatment for postpartum hemorrhage, a leading cause of maternal morbidity and mortality. It is beyond the scope of this report to comment on the more speculative role of prostaglandins in other areas of reproductive pathophysiology, but there is ongoing research in defining the role of prostaglandins in the etiology and treatment of preeclampsia, intrauterine growth retardation, the initiation of term and preterm labor, and the control of uterine blood flow.