With government focus on reducing federal safety net benefits for low-income populations comes news that the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) reduces infant mortality by one-third during the first year of life and lowers the risk of preterm birth for expectant mothers who participate.
The new study, published online in the JAMA Network Open last week, analyzed the live birth certificates of babies born to more than 11 million women between January 1, 2011, and December 31, 2017, from the National Center for Health Statistics, which had recorded insurance coverage and receipt of WIC benefits on the birth certificates, for outcomes of gestational age at birth and death within the first year of life. Of these mothers, about 8 million (73%) had received WIC benefits during pregnancy.
The odds of infant mortality in the first year after birth were lower for babies of mothers who had received WIC benefits during pregnancy (adjusted OR, 0.84; 95% CI, 0.83-0.86). The infant mortality rate was 5.2 deaths per 1000 live births among those who had received WIC benefits during pregnancy and 8.2 deaths per 1000 live births among those who did not (a 36.6% relative risk reduction).
The odds of preterm birth compared with normal term birth were lower among expectant mothers covered by Medicaid who had received WIC benefits than for mothers who did not receive WIC benefits (adjusted proportional odds ratio [OR], 0.87; 95% confidence interval [CI], 0.86-0.87). For extremely premature birth, the prevalence was 0.7% among women who received WIC benefits during pregnancy and 1.2% among those who did not (P<.001); for very premature birth, 1.3% among those who received WIC benefits during pregnancy versus 1.7% for those who did not receive WIC benefits (P<.001); for moderate-to-late premature birth, 10.5% among those who received WIC benefits during pregnancy and 11.2% among those who did not (P<.001).
The study also found that the odds of preterm birth compared with normal gestational age birth were lower for non-Hispanic white, non-Hispanic black, and Hispanic expectant mothers covered by Medicaid who had received WIC benefits during their pregnancies compared with expectant mothers in these groups who had not received WIC benefits. Likewise, the researchers found that odds of infant mortality were lower for these groups of expectant mothers when they had received WIC benefits during their pregnancies than for those mothers who had not participated in the WIC program.
Benefits of WIC nutrition
The researchers note that participation in WIC enables higher overall and protein-specific caloric intake in pregnant women that improve fetal growth and increase infant birth weight. In addition, WIC increases vitamin D intake that may lower the risk of pregnancy-induced hypertension and preeclampsia, major risk factors for fetal mortality, as well as greater maternal iron intake that may increase birth weight for gestational age. Finally, WIC encourages breastfeeding by providing new mothers with guidance and breast pumps. Breastfeeding can reduce the risk of postnatal death between 28 days and 1 year after birth.
The researchers note that one drawback of their study was that it focused on live births and not those pregnancies resulting in miscarriage or stillbirth. They say that participation in the WIC program may reduce the incidence of these outcomes among high-risk pregnancies through better nutrition and prenatal visits.
Also, they call for public health campaigns and increased federal funding so that all expectant mothers who are low income or at risk for poor nutrition can receive WIC benefits during their pregnancies. Currently, about 40% of expectant mothers in the United States participate in the WIC program.