Objective To examine whether an electronic medical record “best practice alert” previously shown to improve antenatal gestational weight gain patient education resulted in downstream effects on service delivery or patient health outcomes. Methods This study involved secondary analysis of data from an intervention to improve provider behavior surrounding gestational weight gain patient education. Data were from retrospective chart reviews of patients who received care either before (N=333) or after (N=268) implementation of the intervention. Pre-post comparisons and multivariable logistic regression were used to analyze downstream effects of the intervention on health outcomes and obesity-related health services while controlling for potential confounders. Results The intervention was associated with an increase in the proportion of prenatal patients who gained weight within Institute of Medicine guidelines, from 28% to 35% (p < .05). Mean total gestational weight gain did not change, but variability decreased such that post-intervention women had weight gains closer to their gestational weight gain targets. The intervention was associated with a 94 gram decrease in mean infant birth weight (p = .03), and an increase in the proportion of overweight and obese women screened for undiagnosed Type 2 diabetes before 20 weeks gestation, from 13% to 25% (p = .01). Conclusions for Practice The electronic medical record can be leveraged to promote healthy gestational weight gain and early screening for undiagnosed Type 2 diabetes. Yet most patients still need additional support to achieve gestational weight gain within Institute of Medicine guidelines.