How exactly the national program achieves these outcomes, however, remains unclear, and study quality shows room for improvement, reported co–lead authors Maya Venkataramani, MD, MPH and S. Michelle Ogunwole, MD, PhD of Johns Hopkins University, Baltimore, and colleagues.
The WIC program, which has been serving low-income women and young children since 1974, “provides supplemental foods, nutrition education and breastfeeding support, screening and referrals to medical and social services, and support for high-risk pregnancies,” the investigators wrote in. The U.S. Food and Nutrition Service administers the program.
The authors conducted a systematic review of 20 observational studies aimed at determining the impacts of WIC participation on maternal, neonatal-birth, and infant-child health outcomes.
All studies included in the review began in or after 2009, when the WIC food package was revised to better address diet-related chronic diseases. For inclusion in the review, studies were required to have a WIC-eligible comparison group. Included research also evaluated the relationship between WIC participation and the prespecified health outcomes.
“We found only 20 studies that fulfilled our rigorous study inclusion criteria for these specific outcomes,” the investigators wrote. “In some areas, the evidence was absent, and in others, the strength of evidence (SOE) was moderate or low.”
Six outcome categories were assessed: maternal morbidity, maternal pregnancy outcomes, maternal health behaviors, maternal health care utilization, child morbidity, and childhood health care utilization. Of these, maternal health care utilization had the most robust body of evidence, while data from studies evaluating maternal morbidity and child morbidity were deemed insufficient.
Based on eligible studies, WIC participation was associated with reduced risks of insufficient weight gain in pregnancy, preterm birth, low infant birthweight, and infant mortality. Participation was also associated with an increased likelihood of infant and child health care utilization, such as routine immunizations.
Growing evidence should drive enrollment
“Growing evidence points to WIC as a way to reduce risk of preterm birth and other adverse outcomes,” said Laura Jelliffe-Pawlowski, PhD, MS, professor at the University of California, San Francisco and a director for the UCSF California Preterm Birth Initiative.
Dr. Jelliffe-Pawlowski, who conducted a California-based study included in the paper, said the review is noteworthy because it shows that WIC-associated benefits are observed across locations.
“It’s not just in California; it’s across the country,” she said. “It’s a national call to action – where there’s partnership between national-, state- and community-level WIC programs – to make WIC as accessible as possible, and reflect community wants and needs, so that more people enroll, and more people stay enrolled.”
Dr. Jelliffe-Pawlowski’s coauthor on the California study, Rita Hamad, MD, PhD, associate professor of family & community medicine at UCSF and associate director of the UCSF Center for Health Equity, encouraged health care providers to drive WIC enrollment, noting that, presently, only one in four eligible 4-year-olds participates.
“Physicians and other health care stakeholders can help patients benefit from this program by encouraging them to sign up, and even by providing sign-up support in the form of a social worker or other staff member,” Dr. Hamad said. “There is also literature on the types of interventions that improve take-up of safety net programs that providers can look to.”