341 Outpatient cervical ripening with foley catheter for elective induction of labor (eIOL) in obese nulliparas

Abstract

Outpatient cervical ripening with a Foley catheter (CF) in nulliparas undergoing eIOL shortens L&D admission to delivery time. As obese women (BMI ≥ 30) have protracted labor, we evaluated if outpatient ripening with a CF may be even more beneficial in this population than in those with BMI < 30. Secondary analysis of an RCT (NCT03472937) in which nulliparas with singletons and modified Bishop score <5 undergoing eIOL ≥ 39wks were randomized to outpatient CF (with scheduled L&D admission the next day) vs inpatient CF. In both groups, oxytocin was initiated on admission. The primary outcome was duration of labor (L&D admission to delivery time); secondary outcomes included rate of cesarean and infections. Outcomes were compared between inpatient and outpatient groups, stratified by BMI ≥ 30 and BMI < 30 after evaluating statistical interactions between randomization group and obesity. Of 126 women in the parent RCT, 69 (55%) had a BMI ≥30. In women with BMI ≥30, women in the outpatient group (vs. inpatient) had lower BMI, decreased GBS+ status, and higher randomization modified Bishop score (p<0.01). Duration of labor and total hospitalization were significantly shorter in the outpatient group (Table). Furthermore, cesarean rate was lower and admission modified Bishop score was higher (3 [2-3] vs. 1 [0-1], p<0.001) with outpatient CF. Adjusting for BMI, labor was on average 6 hours shorter with outpatient CF (mean difference/OR -6.3 [95% CI -10.3, -2.4]). There was no difference in chorioamnionitis (inpatient 13% vs outpatient 29%, p=0.10) or endometritis (inpatient 5% vs outpatient 0%, p=0.50). Tests for interaction between CF group and obesity group were significant–demonstrating an increased beneficial effect with outpatient CF in the obese strata (Table). In obese nulliparas undergoing eIOL, outpatient ripening with CF significantly decreases labor duration, total hospitalization, and the cesarean rate more so than in non-obese women. Given the protracted labor course in these women, a larger study evaluating both safety and efficacy of outpatient CF is warranted.