OXYTOCIN AND ITS RECEPTOR IN PREGNANCY AND PARTURITION - CURRENT CONCEPTS AND CLINICAL IMPLICATIONS

Objective: To present our current understanding of oxytocin and its re ceptors during pregnancy and parturition and their potential clinical applications. Data Sources: A MEDLINE search was conducted for pertine nt articles from 1966 to October 1996 related to oxytocin and its rece ptor and their clinical implications during pregnancy and parturition. Review articles, book chapters, and published trials were also search ed. Methods of Study Selection: Only references in English that were d eemed relevant were used. When possible, human data and sometimes anim al data pertinent to understanding the interaction of oxytocin and its receptors were selected. Tabulation, Integration, and Results: Oxytoc in is synthesized in the hypothalamus and in many reproductive tissues during pregnancy, whereas the receptors are synthesized in reproducti ve tissues. The genes for oxytocin and its receptors are on chromosome s 20 and 3, respectively. Oxytocin and its receptors are regulated by sex steroids and by oxytocin itself. The paracrine and autocrine mecha nisms regulating oxytocin and its receptor within the fetoplacental-ut erine unit are central to the control of uterine contractions and part urition. Such current understanding provides the basis for appropriate oxytocin regimens to induce or augment labor, to inhibit preterm labo r by blockade of oxytocin receptors, and to achieve cervical ripening. Conclusion: Advances in our knowledge of oxytocin and its receptor ha ve provided rational and sound principles for current concepts about t heir role in parturition, the appropriate use of oxytocin to stimulate the pregnant uterus or ripen the cervix, and the use of oxytocin anta gonist to inhibit uterine contractions and preterm labor. (C) 1997 by The American College of Obstetricians and Gynecologists.