WIC prenatal participation and its relation to pregnancy outcomes in Missouri: a second look.

We studied the association of WIC prenatal supplementation with pregnancy outcome using Missouri WIC participants who delivered in 1982 linked with their offspring's birth/fetal death certificates. A 93 per cent match rate resulted in a final study population of 9,411 pregnancies. A control population of like number was acquired by matching on key demographic characteristics. The majority of the results generally confirm the results of a 1980 Missouri study; WIC participation was associated with decreases in low birthweight (7.8 vs 9.2 per cent), prematurity (9.7 vs 12.0 per cent) and inadequate prenatal care (30.5 vs 31.7 per cent), and an increase in mean gestational age (39.9 vs 39.6 weeks). Low birthweight rates were lower for infants of WIC participants in each of the risk categories reviewed. As noted in the 1980 study, duration of WIC of at least seven months was needed before improvements in birthweight outcomes measures were noted.     

A Comparative Analysis of Effects of Early Versus Late Prenatal WIC Participation on Birth Weight: NYS, 1995

OBJECTIVES: This study examined the effects of prenatal participation in the NYS WIC Program on birth weight through enhanced control of selection bias and gestational age bias. Program effects were assessed separately for White, Black, and Hispanic women and subpopulations defined by values of Kotelchuck index of adequacy of prenatal care utilization. METHODS: 1995 New York State Vital Statistics records were linked to WIC certifications, administrative and check redemption files, and to the 1990 federal census of NY county level data. The final data set contained 77,601 records. Birth weight among WIC participants who enrolled early and participated longer were compared to those who enrolled late and participated a shorter time. Selection bias was addressed using classification tree methods as part of a propensity score analysis. Gestational age bias was addressed by analyzing preterm and full-term pregnancies separately. RESULTS: Adjusted estimates showed a significant positive effect of longer prenatal WIC participation on birth outcomes for all groups studied. Infants born to WIC participants who enrolled early were heavier than those who enrolled late by, on average, 70 g for full-term and 129 grams for preterm. Black and Hispanic full-term infants experienced larger WIC effects than Whites (79, 75, 43 g, respectively). Looking at full-term pregnancies using Kotelchuck's index indicated that effects of longer prenatal WIC participation were greatest for the inadequate prenatal care group (83 g). CONCLUSION: Longer prenatal WIC participation was associated with an increase in birth weight overall and for all groups studied. The effect on birth weight of longer participation in WIC was greatest in Black and Hispanic, inadequate and no prenatal care groups.     

WIC prenatal participation and its relationship to newborn Medicaid costs in Missouri: a cost/benefit analysis.

The primary purpose of this study was to determine if WIC prenatal participation is associated with a reduction in Medicaid costs within 30 days after birth, and, if so, whether the reduction in Medicaid costs is greater than the WIC costs for these women. This evaluation of WIC was performed using 7,628 Missouri Medicaid records matched with their corresponding 1980 birth records. This file was then divided into a WIC group containing 1,883 records and a non-WIC comparison group of 5,745 records. WIC participation was found to be associated with the reduction in Medicaid newborn costs of about $100 per participant (95 per cent confidence interval $43,153); mother's Medicaid costs were not affected. For every dollar spent on WIC, about 83 in Medicaid costs within 30 days of birth were apparently saved according to the results of this study (95 per cent confidence interval $.40, $1.30). Reductions in low birthweight rates and NICU admission rates among WIC infants provided two possible reasons for the reduced Medicaid costs associated with WIC food supplementation. As WIC food costs increased, both mean birthweight and newborn Medicaid savings also increased. Because of possible inconsistencies in the data, similar studies are needed in other states.     

The effect of WIC supplemental feeding on birth weight: a case-control analysis

Extant data from prenatal patients in Massachusetts were analyzed to evaluate the effects of WIC supplemental feeding on birth outcomes. A total of 418 pairs of WIC and non-WIC women were directly matched for racial/ethnic group, age, parity, marital status, and income. Participation in WIC supplemental feeding appears to have a positive effect on pregnancy outcome. Participation in WIC is associated with a 107 g increase in mean birth weight (p = 0.012) and a 4.0% decrease in the incidence of low birth weight (p = 0.059). Teenage, Black, and Hispanic women show similar, if not stronger, benefits.     

Prenatal participation in WIC related to Medicaid costs for Missouri newborns: 1982 update

This study replicates a 1980 evaluation of WIC prenatal participation in Missouri by using a file of 9,086 Missouri Medicaid records matched with the corresponding birth records. This file was divided into a WIC group containing 3,261 records and a non-WIC group of 5,825 records. The 1982 results generally confirm the 1980 results, with the 1982 findings showing slightly improved pregnancy outcomes for WIC participants and slightly reduced benefit-to-cost ratios compared with the 1980 findings. In 1982, WIC participation was found to be associated with an increase in mean birth weight of 31 grams and reductions in low birth weight rates (statistically significant) and in neonatal death rates (not statistically significant). The reduction in each rate was 23 percent. WIC participation was also associated with a reduction in Medicaid costs for newborns reported within 45 days of birth amounting to $76 per participant. For every dollar spent on WIC, about 49 cents in Medicaid costs were apparently saved. However, wide 95 percent confidence intervals ($.07, $.90) make it difficult to determine precisely what impact WIC has on Federal and State budget outlays.     

An evaluation of a Medicaid managed maternity program: the impact of comprehensive care coordination on utilization and pregnancy outcomes

The purpose of this study is to evaluate the effectiveness of the implementation of a Medicaid managed maternity care program in a public health department service population, analyzing race-specific models of WIC participation and risk of small-for-gestational age of term. There were 13,095 singleton deliveries during the period 1987-1990 to women with prenatal care in this managed maternity care program. The research design entailed comparison of the intervention group (those receiving regular prenatal care plus comprehensive care coordination in 1989-90) with an historical comparison group of women who received only regular prenatal care in the two years (1987-88). For the intervention groups, black women were 1.7 times and white women 2.1 times more likely to participate in WIC than their comparison groups. The impact of care coordination on term-SGA births indicates a protective odds ratio of 0.851 for black women. Results for white women were not significant. These findings suggest that care coordination is associated with an increase in WIC participation and with lower risk of term-SGA births for black women but not for white women. The overall results add to growing evidence regarding the efficacy of comprehensive care coordination in improving specific pregnancy outcomes and inform our understanding of the evaluation of a comprehensive approach in preventive, community-based intervention.     

Factors influencing early prenatal enrollment in the WIC program

Women's access to prenatal nutrition services was explored using a nationally representative sample of pregnant participants in the Special Supplemental Food Program for Women, Infants, and Children (WIC) in 1984. The probability was examined of the participant entering the program during her first trimester, rather than the second or third trimester. Other research has suggested that length of participation in the program during pregnancy is associated with increased birth weight. The data were adjusted for various personal and local operational factors, such as prior WIC participation, race, age, income, household size, WIC priority level, availability of prenatal or other health services, targeted outreach policies, years of local operation, and local agency size. Previous participation in the WIC Program was the only factor significantly associated with early enrollment (adjusted odds ratio 2.1). Race was marginally significant. Neither the presence of local policies of outreach targeted to pregnant women, nor co-location of WIC services with prenatal or other health services, showed significant effects on early enrollment.     

Effect of the Washington Special Supplemental Nutrition Program for Women,Infants and Children (WIC) on Pregnancy Outcomes

Objectives We determined the effect of the Washington State Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) on adverse pregnancy outcomes. Methods We used a record-linkage retrospective cohort design. We matched records of eligible women who enrolled in Washington WIC from 9/1/1999-12/31/2000 to records of their subsequent birth/fetal death from the Washington State Department of Health to determine their pregnancy outcome between 9/1/1999-10/15/2001 (N = 42,495). We selected comparison women from birth/fetal death records who were WIC-eligible but not on WIC (N = 30,751). We used unconditional logistic regression for analysis. Results WIC was protective for preterm delivery depending on history of abortion and adequacy of prenatal care, being most protective for women with abortion and inadequate prenatal care (Odds ratio (OR) = 0.4; 95% confidence interval (CI) = 0.3–0.5). WIC was protective for low birth weight depending on women’s cervical health, with most protection conferred to those with incompetent cervix (OR = 0.2; 95% CI = 0.1–0.6). WIC was protective for fetal death depending on women’s education, being most protective to those with <12 years of education (OR = 0.2; 95% CI = 0.1–0.3). Conclusions WIC is protective for adverse pregnancy outcomes especially for high risk women.     

Effects of psychosocial risk factors and prenatal interventions on birth weight: evidence from New Jersey's HealthStart program

CONTEXT: Many states developed and implemented multifaceted Medicaid prenatal care programs in the late 1980s in response to expansions in Medicaid eligibility. Although these new programs were based on the presumed relationships between psychosocial risk factors, early prenatal care, prenatal interventions and birth outcomes, research has not verified all of these linkages.
METHODS: Data were collected on 90,117 women who took part in New Jersey's comprehensive prenatal care program, Health Start, between 1988 and 1996. The impact of psychosocial risk factors and prenatal interventions on mean birth weight and the odds of low birth weight (less than 2,500 g) was assessed using ordinary least-squares regression and logistic regression, respectively.
RESULTS: After controls were introduced for social and demographic, psychosocial and behavioral factors, as well as the woman's county of residence and the year of her baby's birth, smoking, drinking and using hard drugs (but not marijuana) during pregnancy were independently associated with reductions in mean birth weight (of 123 g, 29 g and 137 g, respectively) and with increases in the odds of low birth weight (odds ratios, 1.4, 1.2 and 1.7, respectively). However, according to the fully adjusted model, which also controlled for medical risk factors and prenatal services, the interventions designed to reduce those behaviors had no favorable effects on birth weight. In contrast, the receipt of services in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) was associated with an increase in mean birth weight of 22 g (and of 48 g among inadequately nourished women only), and with a reduction in the risk of low birth weight (odds ratio, 0.87).
CONCLUSION: Referrals to WIC services should be a key feature of prenatal care programs for poor women.     

Prenatal WIC Is Associated with Increased Birth Weight of Infants Born in the United States with Immigrant Mothers

BackgroundThe Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) improves health outcomes for participating mothers and children. Recent immigration policy changes increased chilling effects on WIC access and utilization. Associations between WIC participation and neonatal outcomes among infants born to immigrant parents—23% of all births in the United States—are understudied.ObjectiveOur aim was to examine relationships between prenatal participation in WIC and birth weight among infants of income-eligible immigrant mothers.DesignThe study design was repeat cross-sectional in-person surveys.Participants/settingParticipants were 9,083 immigrant mothers of publicly insured or uninsured US-born children younger than 48 months accessing emergency departments or primary care in Baltimore, MD; Boston, MA; Little Rock, AR; Minneapolis, MN; and Philadelphia, PA interviewed from 2007 through 2017.Main outcome measuresOutcomes were mean birth weight (in grams) and low birth weight (<2,500 g).Statistical analysesMultivariable linear regression assessed associations between prenatal WIC participation and mean birth weight; multivariable logistic regression examined association between prenatal WIC participation and low birth weight.ResultsMost of the immigrant mothers (84.6%) reported prenatal WIC participation. Maternal ethnicities were as follows: 67.4% were Latina, 27.0% were Black non-Latina, 2.2% were White non-Latina, and 3.5% were other/multiple races non-Latina. Infants of prenatal WIC-participant immigrant mothers had higher adjusted mean birth weight (3,231.1 g vs 3,149.8 g; P < .001) and lower adjusted odds of low birth weight (adjusted odds ratio 0.79, 95% CI 0.65 to 0.97; P = .02) compared with infants of nonparticipants. Associations were similar among groups when stratified by mother’s length of stay in United States.ConclusionsPrenatal WIC participation for income-eligible immigrant mothers is associated with healthier birth weights among infants born in the United States, including for those who arrived most recently.     

Low Prenatal Weight Gain Among Adult WIC Participants Delivering Term Singleton Infants: Variation by Maternal and Program Participation Characteristics

Objective: To determine the association of maternal and prenatal WIC program participation characteristics with low prenatal weight gain among adult women delivering liveborn, singleton infants at term. Methods: WIC program data for 19,017 Black and White Alabama women delivering in 1994 were linked with birth certificate files to examine the association of anthropometric, demographic, reproductive, hematologic, behavioral and program participation characteristics with low prenatal weight gain. Results: One third (31.0%) had low prenatal weight gain as defined by the Institute of Medicine. The incidence of low weight gain was increased among women who had < 12 years of education, were single, Black, anemic, had low or normal pre-pregnancy body mass index (BMI), increased parity, interpregnancy intervals 24 months, used tobacco or alcohol, or entered prenatal care or WIC programs after the first trimester. After adjusting for selected maternal characteristics, the adjusted odds ratios (AOR) for low weight gain were increased with short interpregnancy intervals (AOR 1.21 to 2.20); tobacco use (AOR 1.16 to 1.40), anemia (AOR 1.20 to 1.25), and second trimester entry into prenatal care (AOR 1.14 to 1.20); the size of the AORs and 95% confidence intervals varied by BMI and racial subgroup. Conclusions: The results of this study suggest that WIC interventions targeting low prenatal weight gain be focused on risk factors present not only during pregnancy, but during the pre- and interconceptional periods as well. Interventions should target low BMI, tobacco use, and anemia, and include attention to nutrition screening and risk reduction among women in postpartum and family planning clinic settings.     

Effects of participation in the WIC program on birthweight: evidence from the National Longitudinal Survey of Youth. Special Supplemental Nutrition Program for Women, Infants, and Children

OBJECTIVES: This study sought to estimate the impact on birthweight of maternal participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). METHODS: WIC estimates were based on sibling models incorporating data on children born between 1990 and 1996 to women taking part in the National Longitudinal Survey of Youth. RESULTS: Fixed-effects estimates indicated that prenatal WIC participation was associated with a 0.075 unit difference (95% confidence interval [CI] = -0.007, 0.157) in siblings' logged birthweight. At the 88-oz (2464-g) low-birthweight cutoff, this difference translated into an estimated impact of 6.6 oz (184.8 g). CONCLUSION: Earlier WIC impact estimates may have been biased by unmeasured characteristics affecting both program participation and birth outcomes. Our approach controlled for such biases and revealed a significant positive association between WIC participation and birthweight.     

Benefits associated with WIC supplemental feeding during the interpregnancy interval

Interpregnancy WIC supplementation was evaluated by comparing maternal nutritional status indicators and subsequent birth outcomes of 703 WIC participants divided into two groups. Study group women received postpartum benefits for 5-7 mo while control group women received postpartum benefits for only 0-2 mo. Both groups received prenatal benefits during each of two study pregnancies. Infants born to study group women had a higher mean birthweight (131 g) and birthlength (0.3 cm) and a lower risk of being less than or equal to 2500 g. Additionally, at the onset of the second pregnancy study group women had higher mean hemoglobin levels and lower risk of maternal obesity. These results suggest that postpartum WIC supplementation has positive benefits for both the mother and her subsequent infants.     

First- and Second-Trimester WIC Participation Is Associated with Lower Rates of Breastfeeding and Early Introduction of Cow's Milk during Infancy

Background

Existing literature suggests prenatal participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) may reduce breastfeeding among low-income mothers. However, little is known about whether the timing of WIC entrance during pregnancy influences infant feeding decisions.

Objective

This study assesses the association between the timing of prenatal participation in WIC and various infant feeding practices, including breastfeeding initiation, breastfeeding for at least 4 months, exclusive breastfeeding, formula feeding, and early introduction of cow's milk and solid food.

Design

Cross-sectional survey matching of birth certificate data to mothers' interviews 9 months after the child's birth. Mothers provided information on participation in the WIC program, infant feeding practices, and sociodemographic characteristics.

Subjects

A nationally representative sample of 4,450 births in 2001 from the Early Childhood Longitudinal Survey-Birth Cohort.

Analyses

Multivariate logistic regression techniques (using STATA 9.0 SE, Stata Company, College Station, TX) estimated the relationship between the timing of prenatal WIC participation and infant feeding practices.

Results

Entry into the WIC program during the first or second trimester of pregnancy is associated with reduced likelihood of initiation of breastfeeding and early cow's milk introduction; and entry during the first trimester is associated with reduced duration of breastfeeding. WIC participation at any trimester is positively related to formula feeding.

Conclusions

Prenatal WIC participation is associated with a greater likelihood of providing babies infant formula rather than breastmilk after birth. Findings also indicate that there are critical prenatal periods for educating women about the health risks of early cow's milk introduction. Given the health implications of feeding infants cow's milk too early, WIC may be successful in educating women on the health risks of introducing complementary foods early, even if direct counseling on cow's milk is not provided.     

Factors associated with rates of participation in WIC by eligible pregnant women.

The relationship between sociodemographic, biological, and prenatal care characteristics, and participation rates of pregnant women in the Special Supplemental Food Program For Women, Infants, and Children (WIC) was studied by interviewing 200 postpartum patients in a Buffalo, NY, hospital between October 1988 and January 1989. Among the 136 women eligible for the program, 94 (69 percent) participated during their index pregnancies. WIC participation was found to be highly associated with source of prenatal care and having made more frequent prenatal visits. WIC was related to having fewer children and earlier initiation of prenatal care. Multivariate analysis showed that program participation remained highly associated with the source of prenatal care and the number of prenatal visits, when combined with other factors considered, such as age, education, marital status, number of living children, and timing of initial prenatal visit. The results suggest the need for a WIC enrollment effort directed to providers of prenatal care, who would be urged to encourage women to seek early and adequate prenatal care through the program.     

Savings achieved by giving WIC benefits to women prenatally.

The Special Supplemental Food Program for Women, Infants, and Children (WIC) provides supplemental food, nutrition and health education, and social services referral to pregnant, breastfeeding, and post-partum women, and their infants and young children who are both low-income and at nutritional risk. A number of statistically controlled evaluations that compared prenatal women who received WIC services with demographically similar women who did not receive WIC services have found WIC enrollment associated with decreased levels of low birth weight among enrolled women''s infants. Several also have found lower overall maternal and infant hospital costs among women who had received prenatal WIC services compared with similar women who did not receive prenatal WIC services. A meta-analysis of the studies shows that providing WIC benefits to pregnant women is estimated to reduce low birth weight rates 25 percent and reduce very low birth weight births by 44 percent. Using these data to estimate costs, prenatal WIC enrollment is estimated to have reduced first year medical costs for U.S. infants by $1.19 billion in 1992. Savings from a reduction in estimated Medicaid expenditures in the first year post-partum more than offset the cost of the Federal prenatal WIC Program. Even using more conservative assumptions, providing prenatal WIC benefits was cost-beneficial. Because of the estimated program cost-savings, the U.S. General Accounting Office has recommended that all pregnant women at or below 185 percent of Federal poverty level be eligible for the program.     

Maternal Smoking and the Timing of WIC Enrollment

Objective: To investigate the association between the timing of enrollment in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and smoking among prenatal WIC participants. Methods: We use WIC data from eight states participating in the Pregnancy Nutrition Surveillance System (PNSS). We adjust the association between the timing of WIC participation and smoking behavior with a rich set of maternal characteristics. Results: Women who enroll in WIC in the first trimester of pregnancy are 2.7% points more likely to be smoking at intake than women who enroll in the third trimester. Among participants who smoked before pregnancy and at prenatal WIC enrollment, those who enrolled in the first trimester are 4.5% points more likely to quit smoking 3 months before delivery and 3.4% points more likely to quit by postpartum registration, compared with women who do not enroll in WIC until the third trimester. However, among pregravid smokers who report quitting by the first prenatal WIC visit, first-trimester enrollment is associated with a 2% point increase in relapse by postpartum registration. These results differ by race/ethnicity; white women who enroll early are 3.6% points more likely to relapse, while black women are 2.5% points less likely to relapse. Conclusions: Early WIC enrollment is associated with higher quit rates, although changes are modest when compared to the results from smoking cessation interventions for pregnant women. Given the prevalence of prenatal smoking among WIC participants, efforts to intensify WIC’s role in smoking cessation through more frequent, and more focused counseling should be encouraged.     

Improved birth outcomes among HIV-infected women with enhanced Medicaid prenatal care

OBJECTIVES: This study evaluated the impact of enhanced prenatal care on the birth outcomes of HIV-infected women. METHODS: Medicaid claims files linked to vital statistics were analyzed for 1723 HIV-infected women delivering a live-born singleton from January 1993 to October 1995. Prenatal care program visits were indicated by rate codes. Logistic models controlling for demographic, substance use, and health care variables were used to assess the program's effect on preterm birth (less than 37 weeks) and low birthweight (less than 2500 g). RESULTS: Of the women included in the study, 75.3% participated in the prenatal care program. Adjusted program care odds were 0.58 (95% confidence interval [CI] = 0.42, 0.81) for preterm birth and 0.37 (95% CI = 0.24, 0.58) for low-birthweight deliveries in women without a usual source of prenatal care. Women with a usual source had lower odds of low-birthweight deliveries if they had more than 9 program visits. The effect of program participation persisted in sensitivity analyses that adjusted for an unmeasured confounder. CONCLUSIONS: A statewide prenatal care Medicaid program demonstrates significant reductions in the risk of adverse birth outcomes for HIV-infected women.     

Unintended pregnancy and preterm birth

About one-third of all pregnancies that result in live births in the US are unintended. Despite the large number of these births, little is known about the outcomes of unintended pregnancies. The purpose of the current study was to evaluate the association between intendedness of pregnancy and preterm birth in a large prospective cohort of women who reported for prenatal care. Pregnant, black, low-income women were enrolled into this study at four hospital-based prenatal care clinics and one off-site hospital-affiliated prenatal clinic in Baltimore City. A self-administered questionnaire to assess demographic and psychosocial data was completed by each woman in the cohort at the time of enrolment in the study. The questionnaire contained an item to measure intendedness of the pregnancy. A total of 922 women comprised the final sample for analysis. For the analyses, intendedness was dichotomised as: intended (wanted now or sooner) vs. unintended (mistimed, unwanted or unsure). Overall, 13.7% of all births to women in the sample were preterm. In a logistic regression model, after controlling for potential confounding by clinical and behavioural predictors of preterm delivery, unintended pregnancy was significantly associated with preterm delivery (adjusted RR = 1.82, 95% confidence interval [1.08,3.08], P = 0.026). In this study of a cohort of urban, clinic-attending, low-income, pregnant black women, unintended pregnancy had a statistically significant association with preterm birth. After adjustment for behavioural and clinical risks, women with unintended pregnancies had almost twice the risk of a preterm delivery as women with intended pregnancies.