1. Department of Ultrasound, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
2. Collaborative Innovation Centre for Maternal and Infant Health Service Application Technology, Quanzhou Medical College, Quanzhou, China
3. Department of Ultrasound, Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
4. Department of Gynecology, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China