While the literature has documented the harmful effects of war and civil conflict on health outcomes at birth, there is little evidence of the impact of a considerable urban intervention on infants’ birth weight. We fill this gap by providing evidence that the urban military intervention called Orion, carried out in the Commune 13 of Medellin in 2002, caused a significant reduction in birth weight in the neighborhoods affected by the intervention relative to other areas. Furthermore, we found that the effects concentrate on married and less educated mothers. Also, we found a reduction in height at birth and a considerable increase in the probability of having a low Apgar score. Although we could not test stress as the primary channel that drove our results, we conclude that stress is possibly one of the mechanisms affecting birth outcomes. These results suggest that it is crucial to analyze the potential unintended effects of urban military interventions.
