To evaluate whether the combination of misoprostol and an intracervical Foley catheter shortens the induction-to-abortion interval compared to misoprostol alone in second-trimester pregnancy terminations.

We conducted a comprehensive search through a search strategy across PubMed, Embase, and Cochrane from the establishment of the database to November 2024. The references from included studies, previous systematic reviews and meta-analyses were searched manually for any additional studies. We performed a systematic review and meta-analysis of RCTs and retrospective cohorts comparing the induction-to-abortion interval in patients with second-trimester terminations of pregnancy. A random effects model was used to calculate the risk ratios (RRs) and mean differences (MDs), with 95% confidence intervals (CIs). Statistical analyses were performed using R, version 4.4.3.

Five studies comprising 657 patients were included, of whom 273 (41.6%) received misoprostol and Foley catheter and 384 (58.4%) received misoprostol alone. Compared with misoprostol alone, misoprostol and Foley catheter combination did not reduce the induction-to-abortion interval (MD -1.29 hours; 95% CI -5.92, 3.33; p=0.58; I²=85%). Furthermore, there were no significant differences in complications such as incomplete abortion (need for surgery) (RR 1.72; 95% CI 0.77-3.85; p=0.18; I²=0%), uterine rupture (RR 0.93; 95% CI 0.10-8.20; p=0.94; I²=0%), hemorrhage (RR 1.07; 95% CI 0.52-2.19; p=0.85; I²=0%), and fever (RR 0.64; 95% CI 0.13-3.29; p=0.59; I²=37%). However, the number of doses of misoprostol in the misoprostol and Foley catheter group was reduced (MD -1.95 doses; 95% CI -3.18, -0.72; p=0.0019, I²=98%).

No reduction in the induction-to-abortion interval was observed in favor of the misoprostol and Foley catheter group. In addition, no differences were observed in need for surgery, uterine rupture, hemorrhage, and fever. However, the misoprostol plus Foley catheter group required a lower total dose of misoprostol required to abortion.