Summary Patients with thrombophilia and/or a history of venous thromboembolism (VTE) exhibit a high risk of thrombosis during pregnancy. The present multicentre study prospectively assessed a prophylaxis strategy, based on a risk score, in pregnancies with increased risk of VTE. Among 286 patients included in the study, 183 had a personal history of VTE (63·98%) and 191 patients (66·8%) had a thrombophilia marker. Eighty nine (46·6%) thrombophilic women had a personal history of VTE. Patients were assigned to one of three prophylaxis strategies according to the risk scoring system. In postpartum, all patients received low molecular weight heparin (LMWH) prophylaxis for at least 6 weeks. In antepartum, LMWH prophylaxis was prescribed to 61·8% of patients with high risk of VTE. Among them, 37·7% were treated in the third trimester only and 24·1% were treated throughout pregnancy. In this cohort, one antepartum‐related VTE (0·35%) and two postpartum‐related VTE (0·7%) occurred. No case of pulmonary embolism was observed during the study period. The rate of serious bleeding was 0·35%. There was no evidence of heparin‐induced thrombocytopenia or osteoporosis. 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.

The specificy of five monoclonal antibodies (P1 -P6) against platelet surface components was determined by immunoprecipitation of surface-labelled platelets from normal donors and patients with known platelet glycoprotein defects, followed by analysis by gel electrophoresis. Three (P2, P4 and P6) precipitated glycoproteins IIb and IIIa and, in addition, P2 precipitated glycoprotein la. PI precipitated normally only glycoprotein Ib also Ia when the platelets were pretreated with neuraminidase. P3 precipitated principally glycoprotein Ia but glycoprotein Ib was also weakly precipitated. The effects of the monoclonals on platelet function were tested. P1 and P2 completely inhibited and P3 slightly inhibited thrombin-induced platelet aggregation. P2 also inhibited collagen-induced aggregation and partially inhibited ADP-induced platelet aggregation. P3, P4 and P6 partially inhibited ADP-induced platelet aggregation. None had any effect on ristocetin-induced aggregation despite Pl and P3 binding to glycoprotein Ib. These results confirm the role of glycoproteins IIb and lIIa in aggregation induced by various agents and suggest that the function of glycoprotein Ib in thrombin-induced aggregation is more important than previously suspected and that glycoprotein la may also be involved in platelet functions.

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.