1 Department of Gynecology, Taipei Show Chwan Hospital, 106 Taipei, Taiwan; Department of Obstetrics and Gynecology, Chang-Hua Show Chwan Memorial Hospital, 500009 Changhua County, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, Kaohsiung Medical University, 80756 Kaohiung, Taiwan. Electronic address: jengcj@gmail.com.