A new study indicates that daily injections of a blood thinner does not effectively decrease the risk of pregnancy complications in women with a tendency to develop blood clots. 

A large-scale, randomized trial was never conducted and until now it’s effectiveness has been unknown. The new study followed 292 women over 12 years and found no difference between the treated and untreated groups.

The blood thinner, low molecular weight heparin (or LMWH), has been widely prescribed as a treatment for women with thrombophilia since the 1990’s. Thrombophilia is a condition that increases the risk of blood clots and affects the approximately 10 per cent of the population.

Original research paper published in the journal The Lancet on July 24, 2014.

Names and affiliations of selected authors

Marc Rodger, Ottawa Hospital Research Institute, Ontario