A health systems reform known as Service Delivery Redesign for Maternal and Newborn Health seeks to make high-quality delivery care universal in Kakamega County, in western Kenya, by strengthening hospital-level care and making hospital deliveries the default option for pregnant women. Using a large prospective survey of new mothers in Kakamega County, we examine several key assumptions which underpin the Service Delivery Redesign policy’s theory of change. We analyze data on place of delivery, travel time and distance, out-of-pocket spending, and self-reported quality of care for 19,127 women prospectively enrolled at antenatal care and surveyed two times after their delivery. We assess womens’ delivery location preferences over the course of pregnancy and compared to previous pregnancies, and compare travel time, out of pocket expenditures, and patient satisfaction for women who deliver in public hospitals versus primary health centers. We find substantial changes in delivery location at population level over time, and for individual women over the course of pregnancy: Facility delivery has increased from 50.4% in 2010 to 89.5% in 2019; and 70% of respondents deliver at a different facility than their reported intention at antenatal care. Out of pocket delivery expenditures are on average 1351 Kenyan shillings (Ksh) in hospitals compared to 964 Ksh in PHCs (p<0.01) . Transport expenditures are 337 Ksh for PHC deliveries versus 422 Ksh for hospitals (p<0.01). Self-reported average travel time is 51 minutes (PHC delivery) vs 47 (hospital delivery) (p=0.78). Average distance to delivery location is 15.1 km for PHC deliveries vs 15.2 km for hospitals (p=0.99). There were no differences in overall patient-reported quality scores, while some subcomponents of quality favored hospitals. These findings generally support key assumptions of the SDR theory of change in Kakamega County, while also highlighting challenges that should be addressed to increase the likelihood of successful implementation.