Body mass index and reported contraceptive use prior to the index pregnancy among Chinese women with unintended pregnancy: a multicenter cross-sectional analysis of a prospective cohort

• Lin ShenChinese Academy of Medical Sciences & Peking Union Medical College
• Jie LiPeking University First Hospital
• Kaiyan PeiChinese Academy of Medical Sciences & Peking Union Medical College
• Xue JiangChinese Academy of Medical Sciences & Peking Union Medical College
• Xiaomei JiangChinese Academy of Medical Sciences & Peking Union Medical College
• Li Zhang
• Zhonglan Xu
• Xiuqing ZhangTaiyuan Maternity and Child Care Hospital
• Lixia Chen
• Fengyan Ren
• Xiuling Guo
• Xiaoman LuoBoai Hospital of Zhongshan
• Qiwei QiQingdao Women and Children's Hospital
• Jun GeTianjin Tanggu Women and Child Health