Tinzaparin safety and efficacy in pregnancy

Unfractionated heparin has largely been replaced by low molecular weight heparin in the treatment and prevention of thrombosis and recurrent miscarriage in pregnancy. There is little information, however, about the efficacy and safety of tinzaparin, which has the advantage of being administered as a single daily dose.

To evaluate the safety and efficacy of tinzaparin use in pregnancy.

We retrospectively reviewed the medical records of women who were prescribed tinzaparin during pregnancy and the puerperium in our hospitals from January 2000 to December 2008. Tinzaparin was given as a single daily prophylactic dose for women with a history of venous thromboembolism (VTE) or recurrent miscarriage and as a single daily therapeutic dose for women diagnosed with VTE. The primary outcomes recorded were thrombosis, bleeding, allergy and thrombocytopenia.

One hundred and forty-nine women aged between 17 and 44 years received tinzaparin in pregnancy and the puerperium over the study period. The dose administered was therapeutic in 21 (14 %) cases and prophylactic in all others. VTE recurred in three women who had a history of VTE (3.6 %). Antepartum and postpartum haemorrhage occurred in 9.7 and 5 % of cases, respectively and two women developed thrombocytopenia but their platelets remained above 100,000/ml. Fifty-seven women (38 %) had regional anaesthesia without complication.

Our study demonstrates a safety profile for tinzaparin in pregnancy that is equivalent to other low molecular weight heparins with the advantage of single daily dosing.