Moving to opportunity? Low birth weight outcomes among Southern-born Black mothers during the Great Migration

Objective: The Great Migration was a mass movement in the United States during the twentieth century of roughly eight million Black Southerners to the Northeast, Midwest, and West. Despite its significance, little is known about the health outcomes associated with this internal migration. This study assessed the relationship between migration and low birth weight among mothers born in the South between 1950 and 1969.

Methods: We used approximately 1.4 million birth records of Black infants maintained by the US National Center for Health Statistics. To tease out the roles of the healthy migrant bias and of destination contexts, we compared two migration groups to Southern non-migrators: (1) migrators moving to the North and (2) migrators moving within the South. Non-migrants were matched to migrants using coarsened exact matching. We estimated the relationship between migration status and low birth weight stratified by birth year cohorts using logistic regression models.

Results: There was positive selection in education and marriage among migrants moving out of the South and within the South. Results showed lower odds of low birth weight in both migration groups compared to Southern non-migrants. The odds ratios of low birth weight were similar in both comparisons.

Conclusion: We found evidence consistent with a healthy migrant bias in infant health among mothers during the last decades of the Great Migration. Despite better economic opportunity, migrating to the North may not have offered additional protection for infant birth weight outcomes.