Introduction: Abortion law reforms have been hypothesized to influence reproductive, maternal, and neonatal health services and health outcomes, as well as social inequalities in health. In 2014, Mozambique legalized abortion in specific circumstances. However, due to challenges implementing the law, there is concern that it may have negatively influenced neonatal outcomes.
Methods: Using a diference-in-diferences design, we used birth history data collected via the Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) between 2004 and 2018 to assemble a panel of 476 939 
live births across 17 countries including Mozambique. We estimated the effect of the abortion reform on neonatal mortality by comparing Mozambique to a series of control countries that did not change their abortion policies. We also conducted stratified analyses to examine heterogeneity in effect estimates by household wealth, educational attainment, and rural/urban residence.
Results: The reform was associated with an additional 5.6 (95% CI=1.3, 9.9) neonatal deaths per 1,000 live births. There was evidence of a diferential effect of the reform, with a negative effect of the reform on neonatal outcomes for socially disadvantaged women, including those with no schooling, in poorer households, and living in rural areas.
Discussion: Given the delay in implementation, our analyses suggest that abortion reform in Mozambique was associated with an initial increase in neonatal mortality particularly among socially disadvantaged women. This may be due to the delay in effective implementation, including the dissemination of clear guidelines and expansion of safe abortion services. Longer-term follow-up is needed to assess the impact of the reform after 2018 when services were expanded. Abortion legal reform without adequate implementation and enforcement is unlikely to be sufficient to improve abortion access and health outcomes.