[1] Natl Res Inst Child Hlth & Dev, Dept Mol Endocrinol, 2-10-1 Okura,Setagaya Ku, Tokyo 1578535, Japan
[2] Keio Univ, Sch Med, Dept Pediat, Tokyo, Japan
[3] Natl Ctr Child Hlth & Dev, Ctr Maternal Fetal Neonatal & Reprod Med, Div Obstet, Tokyo, Japan
[4] Natl Ctr Child Hlth & Dev, Div Reprod Med, Tokyo, Japan