1. Department of Obstetrics and Gynecology, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abeno-ku, Osaka 5454-8585, Japan
2. Department of Obstetrics and Gynecology, Graduate School of Medicine, Osaka Metropolitan University, 1-4-3 Asahimachi, Abeno-ku, Osaka 5454-8585, Japan
3. Women’s Health Care Science, Advanced Care Science Field, Graduate School of Nursing, Osaka Metropolitan University, 1-5-17 Asahimachi, Abeno-ku, Osaka 5454-8585, Japan
4. Department of Medical Statistics, Graduate School of Medicine, Osaka Metropolitan University, 1-4-3 Asahimachi, Abeno-ku, Osaka 5454-8585, Japan