Ethnic differences in the rates of low birth weight attributable to differences in early motherhood: a study from the Third National Health and Nutrition Examination Survey

Abstract

Objective: To estimate the impact of early motherhood (being a mother at < 20 years of age) on ethnic differences in the risk of low birth weight (LBW) in a representative sample (n = 9141) of American infants and children.

Methods: Risks for LBW and the population-attributable fraction due to early motherhood were estimated adjusting for maternal smoking and education in logistic regression models. The contribution of early motherhood to ethnic differences in the risks of LBW was determined using a relative attributable risk estimate that compared Hispanics and Blacks with Whites.

Results: Early motherhood was independently associated with increased risk of LBW in each of the three ethnic groups, adjusting for maternal smoking during pregnancy and education. Hispanic and Black ethnicity were each associated with 15% and 123% increased risk of LBW relative to Whites. The population-attributable fractions of LBW due to early motherhood were 6.2%, 7.4%, and 2.3%, for Whites, Hispanics, and Blacks, respectively. The responses of early motherhood for LBW were different among the three ethnic groups (p < 0.05). Adjusting for maternal smoking and education, 4.8% and 7.4% of the differences in the risk of LBW between Whites and Hispanics and between Whites and Blacks, respectively, were due to differences in early motherhood.

Conclusion: The result of this study underscores the risk of LBW due to early motherhood. Because early motherhood is preventable and avoidable, appropriate public health strategies to educate young women on the need to delay childbearing in these ethnic groups, particularly among Hispanics and Blacks, are warranted.