[1] Univ Chicago, Med Ctr, Sect Adult & Pediat Endocrinol, Dept Pediat,Pritzker Sch Med, Chicago, IL 60637 USA
[2] Univ Chicago, Dept Med, Pritzker Sch Med, Chicago, IL 60637 USA
[3] Univ Chicago, Dept Hlth Studies, Pritzker Sch Med, Chicago, IL 60637 USA
[4] Univ Michigan, Dept Pediat, Ann Arbor, MI 48109 USA
[5] Univ Michigan, Reprod Sci Program, Ann Arbor, MI 48109 USA