OXYTOCIN USE IN OBSTETRIC PRACTICE AND ITS ASSOCIATION WITH POSTPARTUM HEMORRHAGE AND PRIMARY CESAREAN SECTION IN THE UNITED STATES

Background: Oxytocin is a life-saving, high-alert medication.1 While frequently used in obstetric practice to induce or augment labor as well as prevent or treat postpartum hemorrhage, little is known about the levels and patterns of oxytocin use in obstetric practice in the United States. The purpose of this dissertation is to describe how oxytocin is being used in intrapartum care in the US and what are the patters of association with postpartum hemorrhage and primary cesarean section. Methods: This study is a secondary data analysis of the Consortium on Safe Labor Database from the National Institute of Health. The analytic sample consisted of data from women admitted for delivery at 9 of 12 study sites that collected any oxytocin data; women were excluded from analysis if admitted for a pre-labor cesarean section. Descriptive statistics were used to describe oxytocin exposure patterns. Associations between oxytocin exposure and postpartum hemorrhage and primary cesarean section were assessed using multivariable logistic regression. The regression models were then used to predict probabilities. Results: 162,201 births were included in the analysis. Of these, oxytocin dose information had been collected for 54,456 births. 65.7% of women in the sample were exposed to oxytocin during their labor. 2.9% and 14% of women had a PPH diagnosis and primary cesarean, respectively. 66% of births in the sample involved oxytocin exposure during labor. The probability of postpartum hemorrhage was significantly increased at 6,000 mU of total oxytocin dose exposure, while the probability of primary cesarean section was significantly increased at 4,400 mU of total oxytocin dose exposure. Maximum oxytocin infusion rates greater than 10 mU/min and 20 mU/min were associated with increased risks of primary cesarean and postpartum hemorrhage, respectively. Conclusion: The results suggest that oxytocin may be used frequently and has a dose-dependent association with two important obstetric outcomes: postpartum hemorrhage and primary cesarean section. Prospective studies are needed to corroborate this study’s findings and to examine whether oxytocin is being used inappropriately as a way to develop clinical guidance and interventions on its adequate use in obstetric practice