title: Comment to the letter by Dr. S. Matsubara.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hamuro
authors.affiliation: Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka, Japan. dtachibana@med.osaka-cu.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tachibana