We analyzed the effect of changes in health care provider reimbursement mechanisms on pregnancy outcomes. In 2014, the Colombian government implemented a policy that eased the requirements for young adults to keep their health coverage after turning 18. Given the mandatory nature of prenatal care and delivery provision in the country, being insured or not does not affect the admission of pregnant women, but it does impact billing processes for health providers as the responsible payment entity changes. Our study exploits the temporal variation and policy-induced discontinuity by employing a differences-in-discontinuities design. We found that the policy decreased the non-affiliation rate by almost 20%. However, our results indicate that non-affiliation (or, equivalently, health service providers billing the state instead of insurers) is associated with a 44 percentage point decrease in the occurrence of preterm births, as well as a reduction in the likelihood of low birth weight and height.
