[1] Yokohama City Univ, Dept Obstet & Gynecol, Grad Sch Med, 3-9 Fuku Ura, Yokohama, Kanagawa 2360004, Japan
[2] Yokohama City Univ, Dept Stem Cell & Immune Regulat, Grad Sch Med, Yokohama, Japan
[3] Yokohama City Univ, Perinatal Ctr Matern & Neonates, Med Ctr, Yokohama, Japan
[4] Yokohama City Univ Med, Chemotherapy Ctr, Yokohama, Japan
[5] Kanagawa Childrens Med Ctr, Dept Obstet & Gynecol, Yokohama, Japan