1 Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Linkou, and Chang Gung University College of Medicine, Taoyuan (Drs. YS Lin, Weng, and Yen).
2 Taipei Medical University School of Nursing (Dr. SL Lin), Taipei, Taiwan.
3 Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Linkou, and Chang Gung University College of Medicine, Taoyuan (Drs. YS Lin, Weng, and Yen). Electronic address: yen2158@cgmh.org.tw.