Intro: Thrombosis risk is increased during pregnancy and puerperium. There are no recent data on nationwide trends in thrombotic events during the delivery period. Objective: To determine risk factors for thrombotic events in women hospitalized for deliveries. Methods: Data from the Nationwide Inpatient Sample (2000-2010) were used to identify deliveries. Weighted proportion of pregnancy hospitalizations with comorbid thrombotic events, including TIA, ischemic stroke, hemorrhagic stroke, acute MI, and venous thromboembolism, was determined. Poisson regression was used to identify risk factors for thrombotic events. The first multivariable model adjusted for sociodemographic and hospital factors. The second model in addition adjusted for comorbid conditions. Results: There were 4,305,561 women hospitalized for delivery (21.5 million US deliveries), of which 7,242 (0.17%) had thrombotic events in the peripartum period. From 2000-2010, there was an increase in deliveries with associated thrombotic events observed from 7.46/10K to 34.8/10K. Compared to 2000, deliveries with thromboses was 8-fold more likely in 2010 (RR 7.94, 95% CI 1.98-31.93). There was no significant difference in rates from 2000 to 2010 after adjustment for sociodemographic and hospital factors. From 2000-2010, pregnant women with thrombotic events were older, more likely to be White, to smoke, to lack insurance, to be admitted to rural hospitals, and to be admitted in the South or Midwest. After multivariable adjustment for sociodemographics, hospital factors, and comorbidities, admissions in the South (RR 1.26, 95% CI 1.02-1.55) or Midwest (1.33, 95% CI 1.05-1.68), atrial fibrillation (1.28, 95% CI 1.01-1.62), pre-/eclampsia (5.78, 95% CI 4.37-7.66), dyslipidemia (1.72, 95% CI 1.42-2.09), atrial septal defect (14.38, 95% CI 6.76-30.58), and valvular heart disease (1.67, 95% CI 1.25-2.24) were independently associated with higher risk of thrombotic events. Conclusions: From 2000-2010, there was a sizeable increase in deliveries with associated thrombosis. Identification of factors associated with thrombotic events for women hospitalized for normal pregnancies will aid in targeted interventions to screen for, prevent and treat thrombosis related to pregnancy.