1. Department of Obstetrics, Dezhou Women and Children’s Hospital, Dezhou 253000, China
2. Department of Obstetrics, Laoling People’s Hospital, Dezhou 253600, China
3. Department of Reproductive Medicine, The Fourth Hospital of Hebei Medical University (Hebei Tumor Hospital), Shijiazhuang 050000, China
4. Neurosurgery, Affiliated Hospital of Hebei University, Baoding, Hebei 071000, China