Thromboprophylaxis in pregnant Women with a History of Venous Thromboembolism and/or Thrombophilia – Demographic Data and Implementation of Pharmacological Thromboprophylaxis: Preliminary Results from a Prospective Multicenter Study in Germany (GTH VTE-PRO-PREG)

Introduction Venous thromboembolism (VTE) is a major cause of maternal morbidity during pregnancy and the postpartum period. Due to a lack of adequate study data, current thromboprophylaxis guidelines differ in certain aspects. In everyday clinical practice, the decision for or against pharmacologic thromboprophylaxis has to be made on an individual basis weighing the risk of VTE against the risk of adverse side effects such as major bleeding. Method The VTE-PRO-PREG study is a prospective, multicenter, non-interventional observational study aiming to assess current practice of thromboprophylaxis in women at risk of pregnancy-related VTE. Women with a history of VTE, hereditary thrombophilia, or antiphospholipid syndrome (APS) were eligible for this study. The study was conducted at 11 centers across Germany. With this initial analysis we describe the baseline data of the enrolled population, assess the prevalence of VTE risk factors and evaluate whether the pharmacological thromboprophylaxis measures implemented were in accordance with the recommendations of the GTH Working Group on Women’s Health (2020) and the Royal College of Obstetricians and Gynaecologists (RCOG, 2015). Results By the end of the recruitment period on June 30, 2025, a total of 1031 pregnant women had been enrolled, with a mean age of 32 years (range:18-46). The mean gestational age at inclusion was 14 weeks (range: 3-28). A positive history of VTE was documented in 496 women (48%). Hereditary thrombophilia was present in 732 participants with or without VTE (71%), and APS was diagnosed in 55 out of 846 tested women (7%). In 630 women (61%), pharmacological thromboprophylaxis was initiated after confirmation of pregnancy or during the first trimester; 93 women had already been treated with anticoagulants at the time of conception for secondary prevention of previous VTE or for other reasons. Enoxaparin (65%), dalteparin (18%), tinzaparin (14%), fondaparinux (2%) and certoparin (1%) were used. The proportion of women receiving prophylactic, intermediate and therapeutic dosing was 69%, 24%, and 7%, respectively. According to the recommendations of the GTH position paper, thromboprophylaxis was indicated in 584 women and was prescribed to 561 of them (96%). However, in 161 out of 445 women without an indication (36%) anticoagulation was also initiated. When applying the RCOG guidelines, 617 out of 683 women received the recommended thromboprophylaxis (90%), while continuous pharmacological thromboprophylaxis was administered in 105 out of 346 women without an indication (30%). Conclusion Our data indicate that the majority of pregnant women receive thromboprophylaxis in accordance with current guidelines. However, a considerable number of women is treated with anticoagulants as early as the first trimester, despite not meeting the formal indications for thromboprophylaxis outlined by the GTH and RCOG recommendations. This may be due to the overestimation of the risk of VTE in cases of mild thrombophilia. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany