Beyond the Window: Patient Characteristics and Geographic Locations Associated with Late Prenatal Care in Women Eligible for 17-P Preterm Birth Prevention

To reduce the risk of recurrence, women with a history of spontaneous preterm birth (PTB) are recommended to receive 17-hydroxyprogesterone caproate (17-P) injections starting by the 20th week of pregnancy. In women eligible for 17-P, we aimed to identify patient factors and geospatial locations associated with increased risk of presentation beyond 20 weeks gestation.We conducted a secondary analysis of a retrospective cohort study including all women meeting criteria for 17-P within a single academic medical center over a 2-year period. We compared early ( 20 6/7 weeks) with late ( 21 weeks) presenters via demographics, social history, and index pregnancy outcomes using standard and Bayesian statistical models. Geospatial mapping was performed to determine residential areas with high risk for late presentation.Geocoded address data was available for 351 women in whom the mean gestational age at first visit was 14.9 weeks, and 63 of whom were late presenters (17.9%). Younger maternal age, current smoking, and lack of health insurance were predictors of late presentation with greater than 95% probability. Hispanic ethnicity and black race were associated with higher odds of late presentation with 87 and 69% probability, respectively. The area with the latest gestational age at presentation was located within central Durham City and to the northeast.Our study identified patient-level risk factors and geographic locations associated with presentation beyond the recommend window for 17-P initiation. These findings suggest an urgent need for intervention to improve early prenatal care initiation and a target location where such interventions will be most impactful.