evidence for prenatal gender selection†

Objective The normal male to female livebirth sex ratio ranges from 1.03 to 1.07. Higher ratios in China, India and Korea reflect prenatal sex selection. We reviewed sex ratios for US births to investigate potential prenatal sex selection. Methods We reviewed all US livebirths from 1975 to 2002 using National Center for Health Statistics birth certificates in 4-year intervals. We compared the sex ratios of Blacks, Chinese, Filipinos, Asian Indians and Koreans relative to Whites. We also compared the sex ratios by birth order for first, second and third and more births (third+) from 1991 to 2002