Hypertensive disorders of pregnancy (HDP) complicate hundreds of thousands of pregnancies annually in the United States [1]. Preeclampsia, specifically, affects 2–8 % of all pregnancies [2]. It is associated with significant maternal and neonatal morbidity and mortality [3], [4]. Many studies have supported the use of low dose aspirin, a prostaglandin synthesis inhibitor, as a prophylactic measure to reduce the rate of preeclampsia in pregnancy [5], [6]. These studies varied in population risk profile, aspirin dosages, gestational age of prophylaxis initiation, and preeclampsia risk definition [7].

In December of 2014, the United States Preventive Services Task Force (USPSTF) published guidelines for the recommendation of low dose aspirin in patients with risk factors for preeclampsia [8]. In subsequent years, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine subsequently supported the USPSTF guideline criteria and aspirin recommendations for the prevention of preeclampsia [9].

Since the publication of such guidelines, several studies have shown a reduction in the rates of preeclampsia among patients taking aspirin [10], [11], while other studies have shown no benefit to aspirin for preeclampsia prophylaxis [12]. While such studies targeted single or multi-institutions, to our knowledge, no studies have evaluated a broader nationwide approach to HDP following aspirin recommendations. The aim of this study was to determine changes in the rates of HDP in the United States after the publication of aspirin recommendation guidelines by the USPSTF and ACOG.