1. Department of Obstetrics and Gynecology, National Hospital Organization, Okayama Medical Center, Okayama, Japan
2. Department of Surgery, National Hospital Organization, Okayama Medical Center, Okayama, Japan
3. Department of Nephrology, National Hospital Organization, Okayama Medical Center, Okayama, Japan
4. Department of Neonatology, National Hospital Organization, Okayama Medical Center, Okayama, Japan