Personalized thromboprophylaxis using a risk score for the management of pregnancies with high risk of thrombosis: a prospective clinical study

Abstract

Background Patients with thrombophilia and/or a history of venous thromboembolism (VTE) are at risk of thrombosis during pregnancy. A risk score for pregnancies with an increased risk of VTE was previously described by our group (Lyon VTE score). Objectives The aim of this prospective study was to assess the efficacy and safety of our score-based prophylaxis strategy in 542 pregnancies managed between 2005 and 2015 in Lyon University Hospitals. Patients/Methods Of 445 patients included in the study, 36 had several pregnancies during the study period. Among these 445 patients, 279 had a personal history of VTE (62.7%), 299 patients (67.2%) had a thrombophilia marker, and 131 (29.4%) thrombophilic women had a personal history of VTE. During pregnancy, patients were assigned to one of three prophylaxis strategies according to the risk scoring system. Results In the antepartum period, low molecular weight heparin (LMWH) prophylaxis was prescribed to 64.5% of patients at high risk of VTE. Among them, 34.4% were treated in the third trimester only, and 30.1% were treated throughout pregnancy. During the postpartum period, all patients received LMWH for at least 6 weeks. Two antepartum-related VTEs (0.37%; one with a score of < 3 and the other with a score of > 6) and four postpartum-related VTEs (0.73%; three with scores of 3-5 and one with a score of > 6) occurred. No case of pulmonary embolism was observed during the study period. The rate of bleeding was 0.37%. No serious bleeding requiring transfusions or surgery occurred during the study period. Conclusion The use of a risk score may provide a rational decision process to implement safe and effective antepartum thromboprophylaxis in pregnant women at high risk of VTE.

Use of a personalized iterative score to evaluate risk of venous thromboembolism during pregnancy and puerperium

“…The originality of the current VTE risk score lay in its iterative design and the inclusion of VTE risk factors not used in other models, especially for puerperium. The current score could evolve as knowledge of VTE risk factors increases.…”

“…This tool enabled assessment of VTE risk factors to be repeated objectively and iteratively throughout pregnancy. The following risk factors were added to supplement the score devised by Dargaud et al …”

“…This tool enabled assessment of VTE risk factors to be repeated objectively and iteratively throughout pregnancy. The following risk factors were added to supplement the score devised by Dargaud et al 13 : multiparity (>4); smoking (>10 cigarettes per day); varicose veins; high blood pressure; intrauterine growth restriction; pre-eclampsia; heterozygous sickle-cell trait; inflammatory bowel disease; nephrotic syndrome; lupus; postpartum hemorrhage (>500 mL); hemostatic hysterectomy, embolization, or arterial ligation; sepsis; emergency cesarean delivery; and antiphospholipid antibody syndrome (APS).…”

“…Several scores are available to assess VTE risk during pregnancy . The score devised by Dargaud et al . was assessed in a prospective study of a pregnant population at risk of VTE.…”

“…was assessed in a prospective study of a pregnant population at risk of VTE. However, use of this score may lead to underassessment of VTE risk . First, certain risk factors (e.g., pre‐eclampsia) are not taken into consideration.…”