Objective: To characterize the epidemiology, identify trends in prevalence, seasonality, and risk factors for orofacial clefts (OFC), selecting the São Paulo state (SPS) population database.
Design: A population-based study to estimate the OFC prevalence trends in recent years, stratified by maternal age and SPS geographical clusters.
Setting: All live births (LB) with OFC in SPS from 2008-2019.