The most incisive guide to issues facing the American family today . . . An invaluable resource for anyone wishing to stay on the cutting edge of research on family trends.

-W. Bradford Wilcox
Associate Professor of Sociology, University of Virginia 

Best Protection Against LBW

Bryce J. Christensen and Robert W. Patterson

While economists in the Journal of Family and Economic Issues are calling for more studies to measure the effects of marriage on health-related behaviors of African Americans, the Journal of Family Issues dedicated two issues (August and September 2010) to “Examining the Relationship Between Marriage and Health in African American Communities.” The two issues feature nine studies that were selected through a competitive process by Mathematic Policy Research under contract with the U.S. Department of Health and Human Services. Perhaps the most impressive of the studies, by Debbie Barrington of Columbia University, finds that marriage exerts a protective effect against infant low-birth weight (LBW), a major determinant of infant mortality.

Examining data tracking two generations of African-American mothers who participated in the Panel Study of Income Dynamics (PSID) and who gave birth between 1967 and 2005, the public-health researcher quantified not only a protective effect of marriage against LBW but also an effect that has grown stronger over time. In the earlier generation, infants born to unwed mothers had 1.6 times the proportion of LBW of infants born to married mothers. In the latter generation, the risk factor increased to 1.8 times, which Barrington claims is due to “a steeper decline” in LBW among married mothers across the generations. The study also found that among the second-generation cohort, women who gave birth when they were married, and who were themselves born to a married mother, gave birth to infants with the lowest prevalence of LBW. Just 2 percent of these infants had LBW, compared to 9 to 11 percent of infants born to other categories of mothers in the same cohort. These second-generation married mothers enjoyed a 61 percent decrease in odds of infant LBW relative to unmarried peers who were born to an unmarried mother.

Although the protective effects of marriage were not statistically significant in the first generation of mothers, and only diminished slightly in tests that adjusted for a wide-range of demographic and socioeconomic confounding factors, by the second generation the protective effects of marriage against LBW were significant in both statistical models. In the second generation, infants born to married mothers enjoyed a 53 percent decreased odds of LBW relative to their peers born to unmarried mothers, in the crude analysis; 55 percent decreased odds in the adjusted model. Additional tests that incorporated propensity score matching across the generations, as well as sensitivity analyses that adjusted for health of the mother prior to marriage in an attempt to weed out selection effects, made no difference in the correlation between marriage and LBW across both generations.

Given that the original sample of the PSID dataset used in this study, dating back to 1968, was designed to measure the effectiveness of President Johnson’s War on Poverty in helping low-income Americans, these findings represent a wake-up call. For starters, Barrington chronicles a rising protective effect of matrimony at the very time when the percentage of African-American infants born to married mothers experienced what she calls a “precipitous decline.” She also notes that the second generation of African-Americans mothers—relative to the first—were on average better educated, worked more median hours outside the home, were more likely to hold white-collar jobs, and enjoyed higher median incomes. Nonetheless the children born to the second generation were more likely to be born into a poor family, meaning in most cases a single mother. So much for LBJ’s Great Society.

Perhaps this is why the Columbia researcher calls for “policies designed to eliminate barriers to marriage within the African American community” as such policies “over time might also work to diminish the long-standing, two- to threefold increased risk for infant LBW and other adverse perinatal outcomes among African American women relative to White women.” Let’s hope Congress is listening.

(Debbie S. Barrington, “The Increasing Protection of Marriage on Low Birth Weight Across Two Generations of African American Women,” Journal of Family Issues 31.8 [August 2010]: 1041–64).