The effect of the 2009 WIC revision on maternal and child health: A quasi‐experimental study

Abstract

Background The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is the largest U.S. nutrition program for low‐income pregnant women. It was revised in 2009, with the goal of improving nutritional content of food packages, enhancing nutrition education, and strengthening breast feeding support. Few studies have assessed the effects of this revision on perinatal health. Objectives To investigate the impact of the revised WIC program on maternal and child health in a large, multi‐state data set. Methods We conducted a quasi‐experimental difference‐in‐differences analysis, comparing the pre/post changes among WIC recipients to changes among non‐recipients. We adjusted for key sociodemographic covariates in multivariable linear models. We used data from the Pregnancy Risk Assessment Monitoring System (PRAMS) for 18 states from 2004 to 2017. Results The main analysis included 331,946 mother‐infant dyads. WIC recipients were more likely to be younger, Black or Hispanic/Latina, unmarried, and of greater parity. The revised WIC program was associated with reduced likelihood of more‐than‐recommended GWG (−1.29% points, 95% confidence interval [CI] −2.03, −0.56) and increased likelihood of ever breast fed (1.18% points, 95% CI 0.28, 2.08). We also identified heterogeneous effects on GWG, with more pronounced associations among women 35 and older. There were no associations with foetal growth. Conclusions The revised WIC program was associated with improvements in women's gestational weight gain and infant breast feeding.

Do studies evaluating early-life policy interventions fully adhere to the critical conditions of difference-in-differences? A systematic review

“…Pulvera et al did not explicitly discuss clustered SEs, but stated the formula with clustered SEs in the appendix. 29 Spillover was not explicitly reported by Cygan-Rehm and Karbownik. 34 +, meets criteria as proposed in the checklist; ?, not able to score; –, does not meet criteria; N, no; Y, yes.…”

“…Pulvera et al did not explicitly discuss clustered SEs, but stated the formula with clustered SEs in the appendix. 29 Spillover was not explicitly reported by Cygan-Rehm and Karbownik. 34 …”

“…Overall, studies varied markedly in the number and reporting of critical conditions ( table 2 ), with no study reporting and adhering to all seven critical conditions. Three studies carried out appropriate assessment of either five 29 36 or six critical conditions, 34 all of which were published in 2022. Eight studies that adhered to two or less DiD critical conditions 7 19 32 33 35 39 40 42 were published between 2014 and 2021.…”

WIC benefits and evaluation challenges

“…Despite the numerous benefits for infants, children and mothers, WIC, which is up for reauthorisation in 2022, has received substantial recent negative attention because of the formula crisis. The timely article by Pulvera and colleagues in this issue of Paediatric and Perinatal Epidemiology , 2 highlights several beneficial impacts associated with WIC, including higher breastfeeding rates. The study uses a natural experiment, the implementation of the WIC policy in 2009, to examine associations between WIC policy changes and infant and maternal health outcomes.…”