Abstract: Objective To explore the influencing factors of medical abortion outcome, and provide evidences for making intervention measures. Methods A case-control study was adopted with cases who had incomplete or failure abortion after medical abortion, and the controls were those who had complete abortion. The data was analyzed by SPSS16.0. Results The univariate analysis showed that factors such as the surgical abortion history (χ2=4.691, P=0.030), the site of the medical abortion (χ2=13.487, P=0.000), pregnant weeks (χ2=6.747, P=0.009), whether vaginitis before medical abortion (χ2=22.153, P=0.000) were influencing the medical abortion outcome. The multivariate analysis showed that risk factors were the site of the medical abortion (OR=3.693, P=0.009)and whether vaginitis before medical abortion (OR=4.520, P=0.000). Conclusion In private clinics, the ratio of incomplete abortion or failure of medical abortion was more than that in public hospital or family planning clinics. For the women with vaginitis, the possibility of incomplete abortion or failure was greater.

Key words: medical abortion, abortion outcome, inlfuencing factors, logistic regression