1. Reproductive Health Research Centre, National Research Institute for Family Planning, Beijing, China (mainland)
2. Hebei Key Laboratory of Reproductive Medicine, Hebei Reproductive Health Hospital, Shijiazhuang, Hebei, China (mainland)
3. Department of Family Planning, Maternal and Child Health Care Hospital of Zhangjiakou, Zhangjiakou, Hebei, China (mainland)
4. National Health Commission Key Laboratory of Male Reproductive Health, National Research Institute for Family Planning, Beijing, China (mainland)
5. Institute of Pediatric Research, Children’s Hospital of Soochow University, Suzhou, Jiangsu, China (mainland)