1. Department of Obstetrics and Gynecology, Nagoya City University, Graduate School of Medical Sciences, Nagoya, Japan
2. Department of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
3. Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan
4. Center of Maternal-Fetal, Neonatal and Reproductive Medicine, National center for child health and development, Tokyo, Japan