The effects of the Rx Kids unconditional cash prescription programme during pregnancy and infancy on birth outcomes in the USA: a population-based, quasi-experimental study

BACKGROUND: Rates of preterm birth and low birthweight remain high in the USA, in part due to perinatal poverty and societal underinvestment during a crucial window of human development. In 2024, Rx Kids was launched in Flint, Michigan, providing every expectant mother with unconditional cash transfers during pregnancy and infancy. It is the first cash transfer programme in the USA with universal eligibility (ie, community wide and no means testing) that targets the perinatal period. This study aimed to estimate the impact of Rx Kids on birth outcomes. METHODS: In this population-based study, we used administrative data from the Michigan Department of Health and Human Services for all births in the state of Michigan, USA, and a quasi-experimental study design. Our study population comprised all infants born from Jan 1, 2021, to June 30, 2025, to women aged 16 years and older. The primary outcomes were preterm birth (