1. Prenatal Diagnosis Unit, Shenzhen Baoan Maternal and Child Health Hospital, Shenzhen, Guangdong Province, People’s Republic of China;
2. Department of Obstetrics, Shenzhen Baoan Traditional Chinese Medicine Hospital, Shenzhen, Guangdong Province, People’s Republic of China;
3. Prenatal Diagnostic Center, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong Province, People’s Republic of China