[1] Walter Reed Army Med Ctr, ART Program, Washington, DC 20307 USA
[2] Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA
[3] Walter Reed Army Med Ctr, Natl Naval Med Ctr, NIH, Combined Fed Fellowship Reprod Endocrinol & Infer, Bethesda, MD USA
[4] NICHHD, Epidemiol Branch, Bethesda, MD 20892 USA
[5] NICHHD, NIH, Reprod Biol & Med Branch, Bethesda, MD 20892 USA
[6] Inst Washington Inc, ART, Washington, DC USA