1. Department of Obstetrics & Gynecology, Okayama University Graduate School, Okayama 700-8558, Japan
2. Department of diabetology, The Sakakibara Heart Institute of Okayama, Okayama 700-0823, Japan
3. Diabetes Center, Ebina General Hospital, Kanagawa 243-0433, Japan
4. Department of Gynecology and Obstetrics, Aiiku Maternal & Child Health Center, Aiiku Hospital, Tokyo 106-8580, Japan