Developmental outcomes in the first 2 years of life improved in children whose mothers received the revised Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) while pregnant, based on data from approximately 1,200 women.
Maternal nutrition is essential to healthy fetal development, and the WIC was revised in 2009 to align with current dietary guidelines and to support the health of women and children in low-income households, wrote Alice Guan, MPH, of the University of California, San Francisco, and colleagues.
“However, no researchers, to our knowledge, have evaluated effects of this revision on downstream child health or development,” they said.
In a study published in Pediatrics, the researchers reviewed data from mothers and their children who participated in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) longitudinal cohort study conducted in Tennessee between 2006 and 2011. Their quasi-experimental analysis included 700 women who received WIC during pregnancy and 525 women who did not.
The researchers considered core developmental outcomes of child growth, cognitive development, and socioemotional development at age 12 months and 24 months, and age 4-6 years.
Overall, infants of women who received the WIC food package showed significant increases in length-for-age z scores at 12 months of age (.33, representing approximately one-fifth of a standard deviation), compared to infants of women who did not receive the revised WIC package.
In addition, the Bayley Scales of Infant Development cognitive composite score showed a 4.3-point increase at 24 months of age (approximately one-third of a standard deviation) compared to infants of women who did not receive the revised WIC package.
No effects on growth at age 24 months or on cognitive development at age 4-6 years were noted, which suggests that the impact of the WIC program during pregnancy may fade over time, the researchers said.
“The magnitude of the findings in this study represents clinically relevant effect sizes and provides evidence that one of the largest U.S. safety net policies improves developmental outcomes among low-income and marginalized children,” they noted.
The study findings were limited by several factors including the statistical, quasi-experimental design; the reliance on self-reports for information on income, receipt of WIC, and other variables; and a potential lack of generalizability to other states, the researchers noted. However, the results support findings from previous studies and were strengthened by the review of multiple outcomes and use of a longitudinal database, they said.
“These findings provide timely and critical evidence for the role that WIC plays in improving the health of the nation’s most vulnerable populations, suggesting meaningful impacts of the revised WIC food package on child development,” the researchers said. In addition, “considering the relatively modest scope of the 2009 revision, more substantial updates to the program based on up-to-date nutritional guidance may have substantial effects on improving the health of WIC recipients,” they concluded.
Findings support program’s value
“Pediatrics has always had a commitment to reducing disparities in health care, and we are the main clinicians to see many Medicaid patients on a regular basis,” Herschel Lessin, MD, of Children’s Medical Group, Poughkeepsie, N.Y., said in an interview.
“We all know that pregnant women eating nutritiously ought to help child outcomes, but the current study provides an evidence base for something that seems like common sense,” he noted.
Having such an evidence base is helpful to reinforce the value of the WIC program for its intended recipients, especially in the wake of the COVID-19 pandemic when many funding sources are stretched thin, Dr. Lessin said.
The WIC is intended to try to reduce racial and socioeconomic disparities in the most basic form possible, by helping people who are disadvantaged get enough high-quality food to eat, but results of the program’s impact have not been well studied, he said.
“Outcomes are fiendishly difficult to measure,” and the study is subject to the limitations of its statistical nature, he said. But the large sample size adds support to the findings, which are encouraging, Dr. Lessin noted.
Other potential areas for research include comparing the quality of WIC programs in different states, but such research is very difficult, Dr. Lessin noted. However, the findings might encourage states with less robust WIC programs to consider increasing support, he said.
The study was funded by the National Institutes of Health (National Heart, Lung, and Blood Institute); the National Institute on Aging; the University of California, San Francisco, National Center of Excellence in Women’s Health; and the Urban Child Institute. The researchers had no financial conflicts to disclose. Dr. Lessin serves on the editorial advisory board of Pediatric News and had no relevant financial conflicts to disclose.