Soochow University - Department of Epidemiology and Health Statistics, Huazhong University of Science and Technology - Maternal and Child Health Hospital of Hubei Province, Haidian Maternal & Child Health Hospital, Chinese Academy of Medical Sciences - National Research Institute for Family Planning, Soochow University - Department of Obstetrics and Gynecology, Maternal and Child Health Hospital of Hubei Province - Department of Obstetrics, Soochow University - Department of Epidemiology and Health Statistics, Haidian Maternal & Child Health Hospital, Women and Children Health Care Center of Taicang, Haidian Maternal & Child Health Hospital, Soochow University - Department of Epidemiology and Health Statistics, Haidian Maternal & Child Health Hospital, Soochow University - Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases and National Research Institute for Family Planning