The effects of medical abortion and surgical abortion on subsequent pregnancy outcome among nulliparas in China: a systematic review and meta-analysis

Objective To evaluate the effects of medical abortion (MA) and surgical abortion (SA) on subsequent pregnancy outcome among nulliparas in China, so as to provide some reference suggestions for the selection of miscarriages for pregnant women. Methods Systematical search was conducted using PubMed, Cochrane Library, Web of Science, Ovid, Embase, CNKI, China biomedical literature database, Wanfang Database and CQVIP Database. Studies were screened according to the predefined inclusion and exclusion criteria. Review Manager 5.3 software was used for statistical analysis. Results Seven cohort studies with 2 946 cases were included. The incidences of miscarriage, postpartum hemorrhage, placental praevia, placental adhesion and placental remnant occurred in MA group were significantly lower than those occurred in SA group, and their OR(95% CI) were 0.38(0.28-0.52), 0.35(0.25 -0.48), 0.53(0.31-0.90), 0.33(0.23-0.48) and 0.22(0.14-0.35), respectively. No other significant differences were observed between the two artificial abortions groups (all P>0.05). Conclusions Although MA is safer than SA on subsequent pregnancy and is considered a preferred option for nulliparas to terminate their unwilling pregnancy, abortion associated injury still existed for nulliparas in regardless of the type of abortion selected. Thus unnecessary abortion should be avoided.