Abstract Body (Do not enter title and authors here): Background: The association between intrauterine device (IUD) use and pulmonary embolism (PE) risk in hospitalized females of reproductive age is understudied. This study assesses the risk of acute PE and deep vein thrombosis (DVT) in this population.

Methods: Using the National Inpatient Sample (2016–2022), we analyzed 6,441,068 females aged 18–50 years, categorized by IUD use (n=11,930, ICD-10-CM code Z97.5) or non-use. Multivariate logistic regression adjusted for confounders, reporting odds ratios (ORs) and 95% confidence intervals (CIs) for predictors of acute PE and DVT. Statistical significance was set at p<0.05.

Results: Among 11,930 females with IUDs, 265 (2.22%) had acute PE, and 110 (0.92%) had DVT. Females with IUDs had significantly higher odds of acute PE (OR 2.68, 95% CI 2.03–3.53, p<0.01), DVT (OR 1.66, 95% CI 1.07–2.57, p<0.01), and a composite PE/DVT outcome (OR 2.88, 95% CI 1.72–4.83, p<0.01) compared to those without IUDs.

Conclusion: IUD use is associated with a 168% increased risk of acute PE and a 66% increased risk of DVT in hospitalized females of reproductive age. The reliance on ICD-10 codes, which do not distinguish between hormonal and copper IUDs, may underestimate the true thrombotic risk. These findings highlight the need for thorough counseling on thrombotic risks during IUD placement and further research to clarify IUD-specific risks and optimize venous thromboembolism prevention strategies during hospitalization.