Safety of Therapeutic Doses of Tinzaparin During Pregnancy

BACKGROUND/AIMS: Low molecular weight heparin is recommended for the treatment of venous thromboembolism (VTE) during pregnancy. However, there are few reliable data regarding the safety of therapeutic doses of tinzaparin in this setting. The objective of this study was to assess the safety of once-daily therapeutic doses of tinzaparin for the treatment of VTE during pregnancy. METHODS: A retrospective study was carried out in 3 tertiary care centres in France, from 1998 to 2009, including consecutive pregnant women who received once-daily therapeutic doses of tinzaparin (175 IU/kg/day). RESULTS: We analyzed 87 pregnancies in 83 women, representing a total of 13,320 patient-days of treatment. Live-birth rate was 97.8%, with one case of miscarriage (<20 weeks of gestation) and one case of intrauterine foetal death (≥20 weeks). There was no antenatal major bleeding. Major bleeding occurred in 4 women during an emergency caesarean section. No case of heparin-induced thrombocytopenia and no maternal death were reported. There was no neonatal haemorrhage and no case of congenital abnormality. VTE recurred on treatment in one patient and after treatment interruption for several days in 2 other patients. CONCLUSIONS: These results support the safety of once-daily tinzaparin at therapeutic dose for the treatment of VTE during pregnancy.