[1] Eunice Kennedy Shriver Natl Inst Child Hlth & Hum, Div Intramural Populat Hlth Res, Rockville, MD 20852 USA
[2] Univ Utah, Sch Med, Androl & In Vitro Fertilizat Labs, Salt Lake City, UT USA
[3] Univ Utah, Sch Med, Dept Surg, Salt Lake City, UT USA
[4] Univ Utah, Sch Med, Dept Obstet & Gynecol, Salt Lake City, UT 84132 USA
[5] Univ Utah, Sch Med, Dept Human Genet, Salt Lake City, UT 84132 USA
[6] Univ Utah, Sch Med, Dept Family & Prevent Med, Salt Lake City, UT 84112 USA