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U of U Researcher Reports WIC Program Still Associated With Higher Birth Weights

August 2, 2002 — In the last decade, the popularity of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) has increased, leading to a steady increase in federal funding over the last five years. (Congress appropriated $4.4 billion for 2002, up from the $2.1 billion in 1990.) Yet much of WIC’s reputation has been built upon state-not nationally representative-evaluations mostly conducted more than a decade ago.

While past WIC research demonstrated the program’s effectiveness in increasing birth weights, which decreased Medicaid spending, many of the available evaluations contain problems of potential selection bias, according to University of Utah researcher Lori Kowaleski-Jones. She maintains the previous studies don’t account for the myriad reasons a woman who uses the WIC program may differ from a woman who is income eligible to receive WIC benefits, but who does not apply for them.

“There might have been something about a WIC recipient that motivated her to participate to receive funding,” notes Kowaleski-Jones, an assistant professor in the Department of Family and Consumer Studies. “For instance, a mother with a lot of health issues might have been more likely to qualify for WIC, but because of these health issues she may be also more likely to have a low birth weight baby Or, a woman who was concerned enough about her unborn child to apply for WIC benefits might have been more likely to reduce unhealthy behaviors such as smoking and make other healthy choices to promote the outcome of her unborn child. These are examples of biases that were not considered in the old studies, which may have underestimated or overestimated the effects of WIC.”

Kowaleski-Jones began re-evaluating the effectiveness of the WIC program, using data from The National Longitudinal Survey of Youth and information on the prenatal usage of WIC by mothers whose babies were born between 1990 and 1996. Her research, titled “Effects of Participation in the WIC Program on Birth Weight: Evidence from the National Longitudinal Survey of Youth,” was co-authored with Northwestern University’s Greg Duncan and appeared in the May 2002 issue of The American Journal of Public Health.

To reduce the potential for biased results, Kowaleski-Jones studied siblings-and their birth weights-to determine whether prenatal WIC usage by their mother during just one of the pregnancies impacted the birth weight of that baby. “That way I was able to remove those biases that were specific to the mothers. So, to get a more accurate estimate of the impact of WIC on birth weight, I compared two children from the same family,” she says.

Of 453 sibling groups, 71 subgroup pairs had mothers who had used prenatal WIC benefits during just one of the two pregnancies. “My research suggests that, in fact, WIC does have a positive effect on the birth weight and health of an at-risk child,” Kowaleski-Jones states. “Our data suggest that at the 88 ounce (5 pounds, 8 ounces) low birth weight cutoff, WIC benefits increase newborns’ birth weight by six ounces.”

Thirty-year-old Kristie was a WIC clinic director in Utah for six years. In that position, she and her colleagues educated mothers on the importance of proper nutrition for themselves and their babies. After giving birth to a baby boy 10 months ago, Kristie decided to stay home with her new infant. Not long after that her husband lost his job. Now, as a WIC client herself, she says, “The food is the biggest help. I get healthy, well-balanced food for me and cereal for my baby, which has helped with his after-birth weight. Breastfeeding assistance was also very important for us. Even though I knew what I was supposed to do, the baby had a hard time. WIC helped me get past the problems so I could keep nursing him.”

WIC was founded in 1972 to provide food, nutrition, counseling and access to health services for low-income pregnant, breastfeeding and non-breastfeeding postpartum women, infants and children who are found to be nutritionally at-risk. The Food and Nutrition Service (FNS), a federal agency of the U.S. Department of Agriculture, is responsible for administering the WIC Program at the national and regional levels. Each state then decides how to best serve clients in their area.

Kevin Condra, program manager for the Utah Department of Health, which oversees the Utah WIC Program, reports Utah serves more than 61,000 Utah women, infants and children each month. Last year, the WIC program benefited well over seven million women, infants and children nationally.

Typically WIC participants meet with counselors who provide information on health-related issues, but specific nutritional counseling varies from state to state. WIC provides referrals for medical services and distributes vouchers for WIC-approved foods. Those receiving public assistance are eligible for WIC. For more information on the WIC program in Utah, call 801-538-6960 or go to or