African American infants have a 24% greater risk of having a SIDS-related death, compared to the U.S. population as a whole, and experience a 2.5 greater incidence of SIDS than in Caucasian infants. Rates are calculated per 100,000 live births to enable more accurate comparison across groups of different total population size. Research suggests that factors which contribute more directly to SIDS risk—maternal age, exposure to smoking, safe sleep practices, etc.—vary by racial and ethnic group and therefore risk exposure also varies by these groups. Risk factors associated with prone sleeping patterns of African American families include mothers age, household poverty index, rural/urban status of residence, and infants age. More than 50% of African American infants were placed in non-recommended sleeping positions, according to a 2012  study completed in South Carolina, indicating that cultural factors can be protective as well as problematic.The rate of SIDS per 1000 births varies among ethnic groups in the United States:
Central Americans and South Americans: 0.20
Asian/Pacific Islanders: 0.28
Mexicans: 0.24
Puerto Ricans: 0.53
Whites: 0.51
African Americans: 1.08
Native American: 1.24

Society and culture
The rate of SIDS varies vastly among different cultures and countries around the world, with SIDS rates lowest among Asian and Pacific Islander infants. Some evidence supports the hypothesis that SIDS is not an ancient phenomenon and that it appears more commonly in western societies. Much of the popular media portrayals of infants shows them in non-recommended sleeping positions. See also
Fading puppy syndrome
Failure to thrive
Neonatal isoerythrolysis
Newborn care and safety
Sudden unexpected death syndrome
Sudden unexplained death in childhood

References
Further reading
Ottaviani, G. (2014).
From 1995 to 1998, the U.S. SIDS rate for births at 37–39 weeks of gestation was 0.73/1000, while the SIDS rate for births at 28–31 weeks of gestation was 2.39/1000.Anemia has also been linked to SIDS (however, per item 6 in the list of epidemiologic characteristics below, extent of anemia cannot be evaluated at autopsy because an infants total hemoglobin can only be measured during life). SIDS incidence rises from zero at birth, is highest from two to four months of age, and declines toward zero after the infants first year. Genetics
Genetics plays a role, as SIDS is more prevalent in males. There is a consistent 50% male excess in SIDS per 1000 live births of each sex. Given a 5% male excess birth rate, there appears to be 3.15 male SIDS cases per 2 female cases, for a male fraction of 0.61. This value of 61% in the US is an average of 57% black male SIDS, 62.2% white male SIDS and 59.4% for all other races combined. Note that when multiracial parentage is involved, infant race is arbitrarily assigned to one category or the other; most often it is chosen by the mother. The X-linkage hypothesis for SIDS and the male excess in infant mortality have shown that the 50% male excess might be related to a dominant X-linked allele, occurring with a frequency of 1⁄3 that is protective against transient cerebral anoxia. An unprotected male would occur with a frequency of 2⁄3 and an unprotected female would occur with a frequency of 4⁄9.