1. Wright VC, Chang J, Jeng G, Chen M, Macaluso M. Assisted reproductive technology surveillance—United States, 2004. MMWR Surveill Summ 2007;56(6):1–22.
2. Hamilton BE, Martin JA, Sutton PD. Births: preliminary data for 2003. Natl Vital Stat Rep 2004;53(9):1–17.
3. Hamilton BE, Martin JA, Sutton PD. Births: preliminary data for 2002. Natl Vital Stat Rep 2003;51(11):1–20.
4. Gleicher N, Barad D. Unexplained infertility: does it really exist? Hum Reprod 2006;21(8):1951–5.
5. Assisted Reproductive Technology Success rates. National Summary and Fertility Clinic Reports. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention December 2006.