LAUSR

BACKGROUND Males are born in excess of females, expressed as M/T (male/total births), which is expected to approximate 0.515. Racial M/T disparities have been long known. This study was carried out in order to identify such disparities in different races in the United States. DESIGN Monthly male and female live births by race for the entire US were obtained from the website of the Centers for Disease Control and Prevention for 1995-2014 for the four racial groups: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American and White. RESULTS This study analysed 80805992 live births (M/T 0.5117). M/T was Asian or Pacific Islander>White>American Indian or Alaska Native>Black or African American. The M/T gradient across races was highly significant (p<0.0001). CONCLUSIONS The perinatal mortality rate is an important indicator of quality of health care delivery and is expected to approximate 6/1000 births. M/T declines in association with surrogates of socioeconomic status, presumably due to higher stress levels. The lower baseline M/T of Indian or Alaska Native and Black and African American is equivalent to a constant reduction of 3.5-4/1000 male births when compared to White M/T. Race is the most significant variable associated with wealth inequality in the US and may be partially responsible. Sex-selective abortion and the application of a male offspring preference stopping rule is widespread in Asia its immigrants, and in this study is equivalent a constant loss of 3.5 females foetuses per 1000 live births when compared to Whites.