Background

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) improves health outcomes for participating mothers and children. Recent immigration policy changes increased chilling effects on WIC access and utilization. Associations between WIC participation and neonatal outcomes among infants born to immigrant parents—23% of all births in the United States—are understudied.

Objective

Our aim was to examine relationships between prenatal participation in WIC and birth weight among infants of income-eligible immigrant mothers.

Design

The study design was repeat cross-sectional in-person surveys.

Participants/setting

Participants were 9,083 immigrant mothers of publicly insured or uninsured US-born children younger than 48 months accessing emergency departments or primary care in Baltimore, MD; Boston, MA; Little Rock, AR; Minneapolis, MN; and Philadelphia, PA interviewed from 2007 through 2017.

Main outcome measures

Outcomes were mean birth weight (in grams) and low birth weight (<2,500 g).

Statistical analyses

Multivariable linear regression assessed associations between prenatal WIC participation and mean birth weight; multivariable logistic regression examined association between prenatal WIC participation and low birth weight.

Results

Most of the immigrant mothers (84.6%) reported prenatal WIC participation. Maternal ethnicities were as follows: 67.4% were Latina, 27.0% were Black non-Latina, 2.2% were White non-Latina, and 3.5% were other/multiple races non-Latina. Infants of prenatal WIC-participant immigrant mothers had higher adjusted mean birth weight (3,231.1 g vs 3,149.8 g; P < .001) and lower adjusted odds of low birth weight (adjusted odds ratio 0.79, 95% CI 0.65 to 0.97; P = .02) compared with infants of nonparticipants. Associations were similar among groups when stratified by mother’s length of stay in United States.

Conclusions

Prenatal WIC participation for income-eligible immigrant mothers is associated with healthier birth weights among infants born in the United States, including for those who arrived most recently.