Haemostaselogy meets Gender-medicine – Pulmonary embolism in girls

Introduction Within a three-month period, we treated three female patients with significant (intermediate-high to high risk according to the risk stratification of the AWMF guideline) bilateral pulmonary embolism (PE) in our pediatric intensive care unit (PICU). In the context of the 2024 ASH [ 1 ] guideline on the management of PE, the differing clinical courses are discussed. Method The prevalence of PE in childhood is estimated at 0.4–0.9 per 100,000. However, a recently published peer-reviewed study by the American Thoracic Society [ 2 ] reported a significantly higher incidence in this age group than previously assumed. We treated three girls aged 12 to 16 years with bilateral PE in our PICU. All three presented with marked exertional dyspnea (with impaired oxygenation), chest pain (some also leg pain), and significant reduction in physical performance. Results The diagnosis of PE was confirmed in all patients via chest computed tomography (CT). Echocardiography revealed right ventricular strain in all three cases. Two of the girls had no evidence of deep vein thrombosis (DVT) or hereditary thrombophilia. They were also the two older patients (aged 14 and 16 years) and were both at Tanner stage B5/P6. In both cases, the primary risk factor was the use of estrogen-containing oral contraceptives. One of the girls was obese (BMI 33) and had been immobilized for two weeks. Both patients were initially treated with low-molecular-weight heparin (LMWH, enoxaparin) and later transitioned to rivaroxaban (RXB). No recurrence occurred under therapy, and both patients showed good recanalization with no long-term sequelae of PE. The youngest of the three patients presented with extensive DVT and bilateral PE. She was at Tanner stage B2/P2. Further work-up revealed a polymorphism in the protein C gene, consistent with reduced protein C levels (37%). No other risk factors were identified. Due to her impaired general condition and the extensive PE, she initially received systemic thrombolysis with rtPA. Following recurrent re-thromboses, she underwent various pharmacologic and interventional treatments. Ultimately, a combination of LMWH and acetylsalicylic acid (ASA) was successful. The patient was later switched from LMH to RXB. As a side effect of rtPA she developed a parenchymal hemorrhage in the region of the cerebellar tonsil; however, this did not result in any neurological impairment. Due to the extensive DVT, she is currently suffering from post-thrombotic syndrome. Conclusion PE appears to occur significantly more frequently in children than previously assumed, with a possible predominance among female patients. In pediatric patients, symptoms such as dyspnea and chest pain must prompt timely diagnostic evaluation to rule out PE. Management of acute PE should follow the recommendations of the AWMF guideline for adults and the ASH guidelines, with individualized adjustments as needed. Acute thrombolytic therapy or thrombectomy must be carefully considered, with a strict risk-benefit assessment. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany