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CME Credit Offered
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Recording available 2/16-5/2
Recording available 2/16-5/2
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Abstract Award
Abstract Award
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Foundation Awardee

Poster Session 3

Category: Labor

Poster Session 3

(978) The use of mifepristone during second trimester induction of labor: a systematic review and meta-analysis

Thursday, February 12, 2026
10:30 AM - 12:00 PM  
Objective:
To assess whether providing mifepristone before misoprostol is associated with alterations in the duration of labor (DOL) during second-trimester induction of labor (2T IOL). 

Study Design:
We performed a systematic review and meta-analysis of randomized controlled trials (RCT) and cohort studies that included individuals undergoing 2T IOL who received both mifepristone and misoprostol compared to misoprostol between 2000 and 2024 (PROSPERO ID# CRD42024577684). The primary outcome was DOL(in hours) between the first dose of misoprostol to the expulsion of the fetus. Assessment of bias was performed using Cochrane’s Risk of Bias tool and Newcastle-Ottawa Scale for RCTs and cohort studies, respectively. Egger’s test was performed for the assessment of publication bias. A secondary analysis evaluated studies based on the indication for IOL (i.e., intrauterine fetal demise [IUFD] or medication abortion [2T MAB]). A leave-one-out analysis (LOOA) was performed to assess the impact of individual studies on the overall findings.

Results:
Of the 513 abstracts identified, 18 met the inclusion criteria (n= 1341 in 10 RCTs, n=1867 in 8 cohort studies). 17/18 studies demonstrated a low risk of bias. Among RCTs, the addition of mifepristone reduced the DOL by 5.2 hours (95% CI: -6.6 to -3.9, Figure 1). A similar trend was seen in the cohort studies (-4.7 hours, 95% CI: -6.5 to -2.9, Figure 2). Egger’s tests for both RCT and cohort data were non-significant (p=0.08 & p=0.55, respectively). On secondary analyses, data from RCTs demonstrated that mifepristone had a similar effect on DOL in IUFD (n= 276 in 3 studies, -4.8, 95% CI: -7.1 to -2.6) and 2T MAB (n=1065 in 7 studies, -5.49, 95% CI: -7.3 to -3.7). Due to the limited reporting of IUFDs in cohort studies, a secondary analysis could not be performed. The LOOA did not demonstrate any differences in findings.

Conclusion:
Use of mifepristone, in addition to misoprostol, is associated with a shorter DOL during 2T IOL when compared to misoprostol alone. This effect was similar based on indication for 2T IOL (i.e, IUFD or 2T MAB).