1 Department of Obstetrics and Gynecology (Dr. Ota), Tokyo Rosai Hospital, Tokyo, Japan; Fukushima Medical Center for Children and Women (Drs. Ota and Takahashi), Fukushima Medical University, Fukushima, Japan.
2 Fukushima Medical Center for Children and Women (Drs. Ota and Takahashi), Fukushima Medical University, Fukushima, Japan. Electronic address: toshifumi.takahashi@gmail.com.
3 Department of Surgery (Drs. Ajiro, Nohara, Shuno, Kamiyama, and Kobayashi), Tokyo Rosai Hospital, Tokyo, Japan.