Recommendations to improve preconception health and health care—United States: report of the CDC/ATSDR preconception care work group and the select panel on preconception care - Johnson, K; Posner, S F; Biermann, J; CDC/ATSDR Preconception Care Work Group; Select Panel on Preconception Care (MMWR Recomm Rep, 2006)
(RR-6):