[1] Univ Tennessee, Hlth Sci Ctr, Dept Ob Gyn, Div Maternal Fetal Med, Memphis, TN USA
[2] Texas Biomed Res Inst, Dept Pathol, San Antonio, TX USA
[3] Univ Texas San Antonio, Hlth Sci Ctr, Barshop Inst & Pathol, Dept Pathol, San Antonio, TX USA
[4] Univ Tennessee, Hlth Sci Ctr, Dept Pediat, Div Pediat Endocrinol & Metab, Memphis, TN USA