1. Centers for Disease Control and Prevention. Recommendations to improve preconception health and health care – United States: a report of the CDC/ATSDR Preconception Care Work Group and the Select Panel on Preconception Care. MMWR. 2006;55(RR-6):1–23.
2. Lu M, Kotelchuck M, Culhane J, et al. Preconception care between pregnancies: the content of internatal care. Matern Child Health J. 2006;10:S107–12.
3. Ely DM, Driscoll AK. Infant mortality in the United States, 2017: Data from the period linked birth/infant death file. National Vital Statistics Reports; 2019;68(10).
4. National Center for Health Statistics. Overall infant mortality rate in U.S. largely unchanged. News Release, 2 May 2007. http://www.cdc.gov/nchs/pressroom/07newsreleases/infantmortality.htm
5. Kassebaum N, Bertozzi-Villa A, Coggeshall M, et al. Global, regional, and national levels and causes of maternal mortality during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2014;384:980–1004.