NHC Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), School of Pharmacy, Fudan University, Shanghai, China. NHC Key laboratory of Birth Defects Prevention (Henan Provincial Research Institute for Population and Family Planning), Henan, China. Chongqing Health Center for Women and Children, Chongqing, China. Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian, China. Maternal and Child Health and Family Planning Service Center of Huixian City, Henan, China.