Research has long emphasised a ‘critical window’ for nutrition within the first 1000 days of a child’s life, of which the first 270 occur during pregnancy. Current literature on infant health in South Africa focuses on the post-birth period of this window, failing to account for the importance of care while in utero for neonatal health outcomes. Poorly nourished mothers are more likely to give birth to underweight babies, increasing a child’s probability of being stunted. This paper demonstrates the first robust evidence of a ‘pregnancy support’ spillover effect, where mothers who reside in Child Support Grant (CSG) recipient households provide extra nourishment to subsequent children in utero. Recipients of pregnancy support show significant gains in height-for-age standardised scores (HAZ). At the same time, a lack of support hosts limited potential for catch-up growth and highlights the value of prenatal intervention. Average treatment effects are computed by Augmented Inverse Probability Weighted (AIPW) estimators and household Fixed Effects regressions, using the National Income Dynamic Survey (NIDS) data Waves 1 to 5. The existence and importance of pregnancy support spillovers are twofold: current South African literature overlooks this effect, potentially
underestimating the true impact of the CSG. Moreover, the additional gains from prenatal treatment provide nuanced policy insight into the benefits of expanding the current post-delivery CSG into pregnancy.