Elisabet Eppes, Zoë Neuberger, Jennifer Sullivan, and Sonya Schwartz[1]
Participating in WIC Can Help Improve Perinatal and Child Health
Meeting the needs of new and expecting parents and young children, such as ensuring access to nutritious food and preventive health services, improves maternal and child health outcomes. Both Medicaid and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) — programs with shared goals and shared participants — can improve health during pregnancy, the postpartum period, and the early years of a child’s life. Addressing the health-related social needs (HRSNs), including food security, of pregnant and postpartum people and young children enrolled in Medicaid is critical to building a healthy foundation for low-income families. A robust body of research demonstrates that WIC participation is associated with improvements in health and access to health care services, which are central to how the Medicaid program assesses quality of care and health outcomes.
People who are enrolled in Medicaid are automatically income-eligible for WIC, and both programs reach a significant portion of the roughly 2 million eligible infants. But while Medicaid reaches most eligible children and parents,[2] WIC reaches less than half of eligible pregnant people and young children. Among all WIC-eligible Medicaid enrollees, 56 percent do not participate in WIC. Among pregnant Medicaid enrollees, a staggering 85 percent do not participate in WIC even though they are all income eligible.[3]
Increasing WIC participation among Medicaid enrollees is a key strategy for improving maternal and child health outcomes. These include reducing the risk of infant mortality, preterm births, and low birthweight; improving infant feeding practices and diet quality during pregnancy and childhood; and improving child health and development.[4]
Each year, the Centers for Medicare & Medicaid Services (CMS) publishes adult and child measures of quality of care and health outcomes for Medicaid and CHIP enrollees.[5],[6] To support its maternal and perinatal health-focused efforts and allow for more streamlined analysis and reports on maternal and perinatal health goals, CMS also issues a set of maternity quality measures that include indicators from the adult and child sets that states may report.[7]
Increasing WIC participation among eligible Medicaid enrollees can further a state’s efforts to improve performance on child, maternal, and adult quality measures by improving pregnancy and birth outcomes; increasing access to preventive health services, including childhood immunizations; and reducing the risk of overweight and obesity among children.
The table below describes the Medicaid core quality measures that align with WIC, which Core Set(s) each measure corresponds to, the WIC feature that could improve performance, and evidence showing a link between WIC participation and improved outcomes.
| TABLE 1 | |||
|---|---|---|---|
Federal Child, Maternal, and Adult Medicaid Quality Measures Align With WIC | |||
| Core Set (Required Unless Indicated) | Quality Measure | How WIC Aligns With Measure | How WIC Can Enhance Performance on the Measure |
| Child and Maternal | Well-Child Visits in First 30 Months of Life Child and Adolescent Well-Care Visits | WIC can reinforce that infants need frequent well-child visits according to the Periodicity Schedule. WIC connects families to resources such as pediatric care and dental care. | A USDA study following children who enrolled in WIC as infants shows that nearly all (95 percent) have a doctor’s office, health clinic, or other medical facility that they visit for routine physical examinations and wellness checks around the time of the child’s 4th birthday.a |
| Child | Childhood Immunization Status | WIC screens the immunization records of children under age 2 and refers parents to immunization services to help ensure they are up to date. | Several studies have shown that such screening and referrals are effective ways to increase vaccination rates.b Low-income children who have never participated in WIC have immunization rates ranging from 5 to 19 percent lower than current participants, while children who remain in WIC tend to have immunization rates comparable to higher-income children.c |
| Child and Maternal | Low Birthweight | WIC supports healthier pregnancies and births by providing the nutritious foods pregnant and postpartum participants need, referring them for essential medical care, and encouraging them to adopt behaviors associated with improved birth outcomes (such as not smoking). | A recent comprehensive review concludes that WIC participation during pregnancy is likely to reduce the risk of low birthweight by 11 to 24 percent; the review also found that WIC participation may lower the risk of inadequate gestational weight gain among pregnant participants and lower the risk of stillbirth in Black women.d |
| Child | Weight Assessment and Counseling for Nutrition and Physical Activity for Children/Adolescents | WIC supports healthy growth and weight among young children in several ways.e WIC conducts assessments of child weight and growth approximately every six months. WIC nutritionists, registered dietitians, or trained paraprofessionals meet with parents to provide nutrition counseling on child growth and healthy eating and physical activity practices for children. The fruits, vegetables, and whole grains in the food package are consistent with food patterns associated with healthy weight. In addition, supporting higher breastfeeding rates among participating parents may protect against excessive weight gain. | A recent comprehensive review concludes that participating in WIC following the introduction of healthier food packages in 2009 significantly lowered the risk of high weight status among young children (evaluations of the impact of the 2024 WIC food package update on health and dietary outcomes are not available at this time).f A large national study published in 2019 found that the prevalence of obesity in children ages 2 to 4 participating in WIC declined by 2 percentage points between 2010 and 2016.g In addition, children participating in WIC have significantly higher Healthy Eating Index (HEI) scores than eligible non-participants according to one recent study.h A 2024 study found that children who participate in WIC longer have higher HEI scores compared to children who participate for a shorter duration.i The HEI assesses how well the diet aligns with the key recommendations of the Dietary Guidelines for Americans. |
| Child, Maternal, and Adult* | Timeliness of Prenatal Care and Postpartum Care | WIC connects families to resources such as pregnancy and postpartum care. | A study in California found that among people who use public health insurance (primarily Medicaid), WIC participation was associated with reduced risk of late entry (at six months pregnant or more) into prenatal care.j In addition, findings from a recent study suggest that maternal participation in WIC may increase the number of prenatal care visits and reduce costly admissions to neonatal intensive care units.k |
Adult* | Hemoglobin A1C Control for Patients with Diabetes | WIC provides counseling and referrals to help people manage gestational diabetes. It also provides pre- and postnatal nutrition education, which includes information about healthy eating during and after pregnancy, reading food labels when shopping, and cooking healthy meals. WIC also provides healthy foods such as fruits, vegetables, and whole grains. Healthy diets, along with regular exercise, are very important in controlling diabetes, including gestational diabetes.l | There have been no studies examining improvements in Hemoglobin A1C control among WIC participants. A study that examined overall diet quality during pregnancy found that WIC participants consuming the food packages adopted in 2009 had a significantly higher HEI score during pregnancy as compared with income-eligible non-WIC participants.m |
* Reporting of adult quality measures is optional. a Christine Borger et al., “WIC Infant and Toddler Feeding Practices Study-2: Fourth Year Report,” Westat, November 2020, https://fns-prod.azureedge.us/sites/default/files/resource-files/WIC-ITFPS2-Year4Report.pdf. b Jessica Cataldi, Mattie Kerns, and Sean O’Leary, “Evidence-based strategies to increase vaccination uptake: a review,” Current Opinions in Pediatrics, Vol. 32, No. 1, February 2020, https://pubmed.ncbi.nlm.nih.gov/31790027/. c Tracy Thomas et al., “Assessing Immunization Interventions in the Women, Infants, and Children (WIC) Program,” American Journal of Preventive Medicine, Vol. 47, No. 5, November 2014, https://doi.org/10.1016/j.amepre.2014.06.017. d LE Caulfield et al., ”Maternal and Child Outcomes Associated With the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), ”Agency for Healthcare Research and Quality, April 2022, https://doi.org/10.23970/AHRQEPCCER253. e Improvements in children’s body mass index have been shown to improve blood pressure, total cholesterol, insulin, and aerobic fitness. Shelley Kirk et al., ”The Relationship of Health Outcomes to Improvement in BMI in Children and Adolescents,” Obesity Research, Vol. 13, Issue 5, May 2005, https://doi.org/10.1038/oby.2005.101. f Caulfield et al. g Liping Pan et al., “Changes in Obesity Among US Children Aged 2 Through 4 Years Enrolled in WIC During 2010-2016,” Journal of American Medical Association, Vol. 321, No. 23, June 2019, https://doi.org/10.1001/jama.2019.5051; Liping Pan et al., “State-Specific Prevalence of Obesity Among Children Aged 2–4 Years Enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children — United States, 2010–2016,” Mortality and Morbidity Weekly Report, Vol. 68, No. 46, November 2019, http://dx.doi.org/10.15585/mmwr.mm6846a3https://doi.org/10.1001/jama.2019.5051. h Kelin Li et al., “WIC Participation and Dietary Quality Among US Children: Impact of the 2009 Food Package Revision,” Journal of Hunger & Environmental Nutrition, Vol. 17, No. 4, April 2022, https://doi.org/10.1080/19320248.2022.2070444. i Lauren E. Au et al., “Longer WIC Participation Is Associated With Higher Diet Quality and Consumption of WIC-Eligible Foods Among Children 2-5 Years Old,” Journal of the Academy of Nutrition and Dietetics, Vol. 125, No. 10, October 2025, https://doi.org/10.1016/j.jand.2024.11.012. j Rebecca J. Baer et al., “Maternal factors influencing late entry into prenatal care: a stratified analysis by race or ethnicity and insurance status,” The Journal of Maternal-Fetal & Neonatal Medicine, Vol. 32, No. 20, April 2022, https://doi.org/10.1080/14767058.2018.1463366. k Ji Yan, “Is WIC effective in improving pregnancy-related outcomes? An empirical reassessment,” Economics and Human Biology, Vol. 47, December 2022, https://doi.org/10.1016/j.ehb.2022.101197. l Chinaza Awuchi, Chinelo Echeta, and Victory Igwe, “Diabetes and the Nutrition and Diets for Its Prevention and Treatment: A Systematic Review and Dietetic Perspective,” Health Sciences Research, Vol. 6, No. 1, February 2020, https://www.academia.edu/41864763/Diabetes_and_the_Nutrition_and_Diets_for_Its_Prevention_and_Treatment_A_Systematic_Review_and_Dietetic_Perspective. m Rita Hamad et al., “Association of Revised WIC Food Package with Perinatal and Birth Outcomes: A Quasi-Experimental Study,” JAMA Pediatrics, Vol. 173, No. 9, July 1, 2019, https://jamanetwork.com/journals/jamapediatrics/fullarticle/2737097; Rita Hamad et al., “The Impact of the Revised WIC Food Package on Maternal Nutrition During Pregnancy and Postpartum,” American Journal of Epidemiology, Vol. 188, August 2019, https://doi.org/10.1093/aje/kwz098. | |||
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End Notes
[1] This report was prepared with support from Sonya Schwartz, an independent consultant.
[2] Jennifer M. Haley et al., “Uninsurance Rose among Children and Parents in 2019,” Urban Institute, July 2021, https://www.urban.org/sites/default/files/publication/104547/uninsurance-rose-among-children-and-parents-in-2019.pdf.
[3] Courtenay Kessler et al., “National- and State-level estimates of WIC eligibility and WIC program reach in 2023,” Westat, December 2025, https://fns-prod.azureedge.us/sites/default/files/resource-files/wic-eer2023-report.pdf.
[4] Laura E. Caulfield et al., “Maternal and Child Outcomes Associated With the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC),” Agency for Healthcare Research and Quality (US), April 2022, https://doi.org/10.23970/AHRQEPCCER253.
[5] Medicaid.gov, “Adult Health Care Quality Measures,” https://www.medicaid.gov/medicaid/quality-of-care/performance-measurement/adult-and-child-health-care-quality-measures/adult-health-care-quality-measures.
[6] Medicaid.gov, “Child and Adult Health Care Quality Measures,” https://www.medicaid.gov/medicaid/quality-of-care/performance-measurement/adult-and-child-health-care-quality-measures.
[7] Medicaid.gov, “Data and Measurement: Core Set of Maternal and Perinatal Health Measures for Medicaid and CHIP (Maternity Core Set),”https://www.medicaid.gov/medicaid/quality-of-care/quality-improvement-initiatives/maternal-infant-health-care-quality/data-and-measurement.