TOPLINE:

Preterm birth rates in the US increased among low-income households from 2011 to 2021, with Black mothers experiencing the highest rates across all income levels. Black mothers had higher risks for preterm births than White mothers in both the highest and lowest income groups.

METHODOLOGY:

• Researchers conducted a population-based cross-sectional study using data from the Pregnancy Risk Assessment Monitoring System from 2011 to 2021 to assess whether the association between income and preterm birth varied among different racial and ethnic groups in the US.
• They analyzed data of 411,469 mother-infant dyads.
• Participants were categorized by self-reported household income: less than 100% of the federal poverty level (FPL), 100%-199% of the FPL, and 200% or more of the FPL.
• Mothers reported their race and ethnicity, which was categorized as American Indian or Alaska Native, Asian, Hispanic, non-Hispanic Black, non-Hispanic White, other, or multiracial.
• Temporal trends in preterm birth (birth at less than 37 weeks’ gestation) were assessed by income categories.

TAKEAWAY:

• From 2011 to 2021, the rates of preterm birth increased from 9.7% to 11.1% among those with household incomes of less than 100% of the FPL and from 7.8% to 10.0% among those with household incomes of 100%-199% of the FPL (P < .001 for both).
• Black mothers had the highest preterm birth rates across all income levels, with the risk for preterm birth being 19% greater in Black mothers in the lowest income group (adjusted relative risk [aRR], 1.19; P < .001) and 13% greater in those in the highest income group (aRR, 1.13; P < .001) than White mothers in the lowest income group.
• White mothers in the highest income group had a lower risk for preterm birth than their counterparts in the lowest income group (aRR, 0.91; P = .03).

IN PRACTICE:

“Interventions focused solely on addressing income disparities may be insufficient to eliminate the racial and ethnic disparities in preterm birth observed. A multifaceted approach is needed that addresses both socioeconomic factors and the underlying structural inequities that disproportionally affect Black communities,” the authors wrote.

“As highlighted by the authors, the ways in which poverty is associated with the health of pregnant people and their infants are multifactorial, and solutions must go beyond individual-level provision of resources,” an expert wrote in an invited commentary.

SOURCE:

The study was led by Erika G. Cordova-Ramos, MD, of the Department of Pediatrics at the Boston Medical Center in Boston. It was published online on January 2, 2026, in JAMA Network Open.

LIMITATIONS:

Income was self-reported in categorized ranges. The study design did not allow for conclusions about cause and effect, and other unmeasured factors might have affected the results, even after considering important sociodemographic and pregnancy-related variables.

DISCLOSURES:

Some authors were supported by the Robert Wood Johnson Foundation Harold Amos Medical Faculty Development Program and/or the Eunice Kennedy Shriver National Institute of Child Health and Human Development. No relevant conflicts of interest were disclosed by the authors.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.