Objective To compare the effects of two different drug regimens on inducted abortion in scar pregnancy in midtrimester, in order to provide evidence for clinical work.

Methods Literatures on the effects of different drug regimens on labor induction in second trimester of scar pregnancy during 2012 − 2022 were searched from database of Wanfang, Weipu, CNKI, PubMed, Cochrane Library, Embase and Web of Science. They were divided into ‘mifepristone + misoprostol’ group and ‘mifepristone + esacridine’ group, and the effect of induced abortion were compared between 2 groups. According to the way of administration of misoprostol, they were divided into 2 subgroups, namely ‘mifepristone + oral misoprostol’ group and ‘mifepristone + vaginal misoprostol’ group. Review Manager 5.2 software was used for meta-analysis, and subgroup analysis were performed for success rate of induced abortion and the volume of postpartum haemorrhage.

Results Sixteen articles were involved in our study. The success rate of induced abortion in the ‘mifepristone + misoprostol’ group was significantly higher than that of the ‘mifepristone + exacridine’ group (RR = 0.97, 95% CI: 0.94 − 1.00; P = 0.05), while the period of induced abortion (SMD = 3.33, 95% CI: 1.91 − 4.74; P < 0.05) and total labor time (SMD = 1.29, 95% CI: 0.24 − 2.34; P = 0.02) were significantly shorter in the ‘mifepristone + misoprostol’ group than those in the ‘mifepristone + exacridine’ group. However, there were no differences between 2 groups in terms of the time from medication use to uterine contraction (SMD = 0.04, 95% CI: − 1.52 − 1.61; P = 0.96), the volume of postpartum hemorrhage (SMD = 0.07, 95% CI: − 0.26 − 0.39; P = 0.69), the incidence of residual placental membrane (SMD = 0.95, 95% CI: 0.53 − 1.71; P = 0.87), and the rate of soft birth canal injury (SMD = 2.22, 95% CI: 0.83 − 5.97; P = 0.11). Subgroup analysis showed that there were no differences between oral misoprostol and vaginal misoprostol group in terms of the success rate of induced abortion and the volume of postpartum hemorrhage (all P > 0.05).

Conclusion ‘Mifepristone + misoprostol’ is superior to ‘mifepristone + esacridine’ in aspects of success rate, the period, and total labor time of induced abortion in scar pregnancy, which is worth of clinical promotion. In addition, the way of misoprostol administration might have no effect on the result of induced abortion.