Does WIC Reduce Prenatal Substance Use?
Research Center: Institute for Research on Poverty, University of Wisconsin-Madison
Investigator: Waehrer, Geetha
Institution: Pacific Institute for Research and Evaluation
Pacific Institute for Research and Evaluation
11710 Beltsville Drive, Suite 300
This study examines the effect of the Special Supplemental Nutrition Program
for Women, Infants, and Children (WIC) on prenatal use of alcohol and
tobacco of participating pregnant women. Previous research shows that smallscale
interventions similar to those provided in a WIC clinic can have an effect
on preventing or reducing prenatal smoking or drinking. Yet few studies have
examined the impact of WIC education on prenatal substance use. This is an
important issue since prenatal exposure to alcohol, drugs and tobacco is one of
the leading preventable causes of birth defects, mental retardations, and
neurodevelopmental disorders in the United States. Pregnant WIC participants
exhibit these behaviors: 29 percent smoke during pregnancy, 16 percent drink
alcohol, and 8 percent use marijuana. Such behaviors directly undermine
WIC’s goal of improving birth outcomes of poor children.
The study also examines the effect of state policies towards pregnant
substance abusers on both WIC participation and prenatal substance use.
These policies—which range from supportive (e.g., treatment and/or education)
to punitive (e.g., child welfare investigations, termination of parental
rights over prenatally exposed children, civil retention in a drug treatment
facility for prenatal drug use)—may affect the participation of pregnant
women in public health services. Yet little is known about their effects. The
research reviews whether these policies change rates of prenatal drinking or
smoking or have the unintended consequence of keeping women away from
needed social services, including WIC.
Data from the National Longitudinal Survey of Youth, 1979 (NLSY) are
used to study the effect of WIC on prenatal smoking and drinking. NLSY
data are supplemented with information on state policies towards pregnant
substance users. These data are rich enough to allow two-stage estimation
models that control, where necessary, for sample selection into the pool of
WIC participants. County characteristics help identify WIC effects in the
two-stage models. The analysis incorporates the presence of multiple sibling
families in the NLSY and estimate WIC effects using fixed-effect models.
Study results indicate that WIC’s non-nutrition activities play a role in
moderating prenatal drinking and smoking. The results were stronger for
white mothers and for models of smoking reduction while pregnant.
However, WIC participation did not result in complete abstinence from
smoking or drinking for all pregnant WIC women. The results are consistent
with the literature showing that brief interventions can have a positive but
limited effect on maternal behavior for the duration of the pregnancy.
The results suggest that, for nonwhite mothers, the State requirements for
prenatal drug testing may discourage the use of health services like WIC.
Instead, States with education and prioritized treatment may be more
successful at exposing pregnant women to WIC services, including its array
of nutrition-related activities Although punitive State approaches have
received much media attention, these policies may not be a major factor in
WIC participation, though this result could be driven by the limited number
of affected pregnancies in the data.
The study suggests that pregnancy is a “teachable moment” when pregnant
women are responsive even to small interventions that appeal to their desire
to have healthy children. WIC provides a unique opportunity to engage lowincome
women who are at higher risk for prenatal substance use and unfavorable
birth outcomes. WIC appears to affect the behavior of pregnant
women even though its nutrition education sessions are not required for the
receipt of other benefits.