Explaining the Link Between Paternal Socioeconomic Position and Small for Gestational Age Birth: The Effect of Maternal Unhealthy Behaviors.

OBJECTIVE

To determine the proportion of small for gestational age (weight < 10th percentile, SGA) births among fathers with lifelong low (compared to high) socioeconomic position (SEP) attributable to white and African-American women's unhealthy pregnancy-related behaviors.

METHODS

Oaxaca-Blinder decomposition methods were conducted on the Illinois transgenerational dataset of infants (1989-1991) and their Chicago-born parents (1956-1976) with appended US census income data. The neighborhood income of father's residence at the time of his birth and at the time of his infant's birth were used to estimate his lifetime SEP. Maternal unhealthy pregnancy-related behaviors were defined as cigarette smoking, inadequate prenatal care, and/or low weight gain during pregnancy.

RESULTS

Among African-American women, births (n = 4426) to fathers with lifetime low SEP had an SGA rate of 14.8% compared to 12.1% for those (n = 365) born to fathers with lifetime high SEP (p < 0.0001). Among white women, births (n = 1430) to fathers with lifetime low SEP had an SGA rate of 9.8% compared to 6.2% for those (n = 9141) born to fathers with lifetime high SEP (p < 0.0001). Adjusting for maternal age, marital status, education, and parity, African-American and white women's unhealthy pregnancy behaviors accounted for 25% and 33%, respectively, of the disparity in SGA rates among infants of lifetime low (compared to high) SEP fathers.

CONCLUSION

A significant proportion of the disparity in SGA rates between fathers with lifelong low (compared to high) SEP is explained in both races by maternal unhealthy pregnancy behaviors.