Congenital Malformations in Offspring of Native American Women in California, 1983-2008

Objective: As one of the leading causes of infant mortality, very little information has been published regarding the risks of various birth defects among infants born to Native American women. This study uses data from the California Birth Defects Monitoring Program's population-based birth defects Registry. The objective was to explore the risks of selected congenital malformations in offspring of Native American versus non-Hispanic white women in California.

Methods: Data were derived from the California Birth Defects Monitoring Program, a population-based active surveillance system for collecting information on infants and fetuses with congenital malformations using multiple source ascertainment. Approximately 13,810,590 million births (live born and fetal deaths) occurred during the ascertainment period, 1983-2008. Information on maternal race/ethnic background was obtained from California birth certificate and fetal death files. Native American and non-Hispanic white women delivered 80,124 and 4,829,759 births, respectively.

Results: Relative risks for the 20 groupings of malformations designated by three-digit British Pediatric Association diagnosis codes ranged from .79 (anencephalus, among infants born to Native Americans) to 1.73 (integument anomalies, among infants born to Native Americans). Out of the 20 groupings, 16 relative risk estimates suggested elevated risks for Native Americans relative to non-Hispanic white births.

Conclusion: Our results suggest that Native American women having babies in California are at both lower and higher risk for some of the malformations included in this study when compared to non-Hispanic whites. Further analyses of these data will provide additional insight.