1. Department of Obstetrics and Gynecology, Institute of Health Biosciences, the University of Tokushima Graduate School, Tokushima
2. Department of Community Medicine for Cardiology, Tokushima University Graduate School of Medicine, Tokushima, Japan
3. Ultrasound Examination Center, Tokushima University Hospital, Tokushima, Japan
4. Perinatal Medical Center, Shikoku Medical Center for Children and Adults, Japan
5. Department of Cardiovascular Medicine, Tokushima University Graduate School of Medicine, Tokushima, Japan