The Low-Molecular-Weight-Heparin, Tinzaparin, Is Effective and Safe in the Treatment and Prophylaxis of Venous Thromboembolic Disease during Pregnancy.

During pregnancy the incidence of venous thromboembolism (VTE) is approximately 6 times higher than in age-matched, non-pregnant women and venous thromboembolism remains the most common cause of maternal morbidity and mortality. Low-molecular-weight-heparins are recommended for treatment of VTE during pregnancy and for prophylaxis of VTE in pregnant women with major thromboembolic risk factors. We used tinzaparin for prophylaxis and treatment of VTE in 305 consecutive pregnant women referred to the Thrombosis Centre, Gentofte University Hospital, from 1997 to 2004. In 268 pregnancies the mothers had thrombophilia, 52 women were admitted with acute VTE and 184 had previous VTE. Other clinical risk factors included previous bad obstetric outcome, recurrent miscarriages, cardiac disorders or previous thromboembolic stroke. An individual risk assessment of each pregnant woman was performed. Very high risk females were treated with tinzaparin 90 – 100 IU/kg bid, high risk females were treated with tinzaparin 100 – 125 IU/kg daily and women with moderate risk were treated with 50 – 75 IU/kg daily.

302 of 305 pregnancies (99 %) in 263 females resulted in 310 healthy babies. 306 of 310 babies had appropriate birth weight for gestational week and all babies had normal Apgar score. Two females had miscarriages (week 10 and 20) and 1 female had an elective abortion. No females had pulmonary embolism. Deep venous thrombosis occurred in 4 of 305 pregnancies = 1,3 % (week 6, 11, 27 and one day postpartum). Wound hematoma was observed after cesarean section in two women and postpartum bleeding episodes (700 – 1500 ml) were observed in 7 women (4 had severe vaginal or cervical tearings, 2 had retained placenta and 1 had placental abruption). We found no incidence of thrombocytopenia or symptomatic osteoporosis.

We find that individually dosed tinzaparin is safe and seems effective in the prevention of thromboembolic complications during pregnancy. Individual risk stratification is recommended.