Background. Heat shock proteins (Hsp) were discovered over 50 years ago and are commonly called ‘stress proteins’. Hsp proteins play an important role in a cell, in that they provide protection against cellstress factors and environmentally negative factors. The most conservative, and the best known, heat shock proteins are Hsp 70 subfamily proteins. It has been suggested that an increase of Hsp 70 in the blood during pregnancy has a negative impact. The aetiology of recurrent miscarriages in more than 60% of women remains unexplained. Therefore the aim of this study was to evaluate the usefulness of Hsp 70 assessment in the diagnosis of recurrent miscarriages.Material and methods. The study group consisted of 100 women (aged 36.0 ± 4.9 years) who had experienced repeated miscarriages. The reference group consisted of 60 women (aged 36.1 ± 3.6 years), who had been pregnant at least twice and who had given birth by a spontaneous labour without complications. Hsp 70 was determined in the serum.Results. We found no significant differences in the Hsp 70 concentration between the women with recurrent miscarriages and the reference group. While median serum Hsp 70 was the most elevated in the women with the highest number of miscarriages, this difference was not significant.Conclusion. Based on the obtained results, it is difficult to determine whether Hsp 70 plays a causative role in recurrent miscarriages. However, taking into account the fact that the role of Hsp 70 in the course of normal and pathological pregnancy is not yet completely understood, it may be worth expanding the study to include a larger group of women with recurrent miscarriages
