Objective:To explore the association of induced abortion with subsequent stillbirth.Methods:The data collected from the National Free Pre-Pregnancy Health Examination Project in Yunnan Province between 2010 and 2017 were used in this analysis. Information on women's background characteristics, pregnant history, disease history, physical examination, etc. were recorded. After their pre-pregnancy health examination, women were routinely followed up and any pregnancies and pregnancy outcomes were recorded. By using SPSS20.0 and SAS9.4 software, we employed description analysis, Chi-square tests, stratified analysis and multivariate logistic regression for data analysis.Results:A total of 174 782 pregnancies were included in this analysis, and the total incidence rate of stillbirths was 0.64% (1119/174 782). The incidence rate of stillbirths in the group of women who had a previous history of induced abortion (exposed group) was 0.83% (333/40 216), which was significantly higher than 0.58% (786/134 566) in the non-induced abortion group (unexposed group). Results of unconditional multivariate logistic regression analysis demonstrated that, compared with unexposed group, the risk of stillbirth in exposed group was higher in those with 1 and 2 or more induced abortions ( OR=1.22, 95% CI=1.05-1.41; OR=1.33, 95% CI=1.08-1.64). The risk of stillbirth was significant lower in women who conceived in 2011-2016 than in 2010 ( OR=0.66, 95% CI=0.51-0.85). Mother's ethnicity, age, education level, parity and body mass index (BMI) before pregnancy were significantly associated with the risk of stillbirth. Women's occupation, previous histories of premature birth, stillbirth and natural abortion were not associated with subsequent stillbirth. Conclusion:Induced abortion is associated with an increase of the risk of subsequent stillbirth. Mother's ethnicity, age, education level, parity and BMI are significantly associated with the risk of stillbirth. Overweight and obesity before pregnancy increase the risk of stillbirth.

Objective:To explore the association of induced abortion with subsequent stillbirth.Methods:The data collected from the National Free Pre-Pregnancy Health Examination Project in Yunnan Province between 2010 and 2017 were used in this analysis. Information on women's background characteristics, pregnant history, disease history, physical examination, etc. were recorded. After their pre-pregnancy health examination, women were routinely followed up and any pregnancies and pregnancy outcomes were recorded. By using SPSS20.0 and SAS9.4 software, we employed description analysis, Chi-square tests, stratified analysis and multivariate logistic regression for data analysis.Results:A total of 174 782 pregnancies were included in this analysis, and the total incidence rate of stillbirths was 0.64% (1119/174 782). The incidence rate of stillbirths in the group of women who had a previous history of induced abortion (exposed group) was 0.83% (333/40 216), which was significantly higher than 0.58% (786/134 566) in the non-induced abortion group (unexposed group). Results of unconditional multivariate logistic regression analysis demonstrated that, compared with unexposed group, the risk of stillbirth in exposed group was higher in those with 1 and 2 or more induced abortions ( OR=1.22, 95% CI=1.05-1.41; OR=1.33, 95% CI=1.08-1.64). The risk of stillbirth was significant lower in women who conceived in 2011-2016 than in 2010 ( OR=0.66, 95% CI=0.51-0.85). Mother's ethnicity, age, education level, parity and body mass index (BMI) before pregnancy were significantly associated with the risk of stillbirth. Women's occupation, previous histories of premature birth, stillbirth and natural abortion were not associated with subsequent stillbirth. Conclusion:Induced abortion is associated with an increase of the risk of subsequent stillbirth. Mother's ethnicity, age, education level, parity and BMI are significantly associated with the risk of stillbirth. Overweight and obesity before pregnancy increase the risk of stillbirth.