Poster session II Diabetes, labor, medical-surgical-disease, obstetric quality & safety, prematurity, ultrasound-imaging: Abstracts 237 – 386| Volume 206, ISSUE 1, SUPPLEMENT , S144, January 01, 2012

301: Induction of labor with oxytocin: should oxytocin be held?


      Once active labor is reached in women undergoing induction of labor, common practice is to continue oxytocin intravenously. However, continued infusion may lead to desensitization of the receptors to both exogenous and endogenous oxytocin. Our objective was to determine whether there is an increase in the cesarean delivery rate and labor length in women undergoing induction when oxytocin is discontinued in the active phase of labor.

      Study Design

      This was a prospective randomized controlled trial of women undergoing induction of labor with a singleton gestation ≥37 weeks during February 2009-August 2011 at Lehigh Valley Health Network. Women were randomly assigned to either oxytocin as routinely used (ROUT) or oxytocin discontinuation (DC) once in active labor. Induction method and labor management were otherwise left at the discretion of the obstetrician. Analysis was by intention to treat.


      241 patients were eligible for study analysis: 119 patients randomized to ROUT and 122 patients randomized to DC once active labor was reached. 23.8% (n=29) randomized to DC were continued on oxytocin once active. Oxytocin was restarted in 46.7% of patients randomized to DC (n=57). Cesarean delivery (CD) rate was similar between the groups (ROUT 25.2% [n=30] vs. DC 19.7% [n=24], p=0.30). The table shows a slightly higher chorioamnionitis rate and slightly longer active phase in those randomized to DC, although not statistically significant. In adjusted analysis, the rate of chorioamnionitis was not different by randomization arm but was explained by a longer active phase of labor [AOR 1.33 (95% CI 1.12, 1.58), p=0.001].
      Tabled 1
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      The CD rate was not different among women undergoing induction of labor when oxytocin was discontinued in the active phase. However, a higher rate of chorioamnionitis was related to a longer active phase of labor. Discontinuation of oxytocin once active labor is reached may decrease receptor desensitization without significantly increasing the CD rate, but longer labor duration is associated with an increased risk of chorioamnionitis.