Two women are presented who were diagnosed of thrombotic thrombocytopenic purpura (TTP) during their first pregnancies, leading in both cases to spontaneous abortion. Both patients improved after plasma exchange or fresh plasma infusion. Two new pregnancies on each patient, closely watched on gynaecological and haematological grounds, led to TTP reactivation. Obstetrical and haematological management was similar for the two women (fresh-frozen plasma administration) but it yielded different results, since, although the risks for the mothers were controlled, one of the patients gave birth successfully on two occasions while the other developed stillborns on two occasions as well. These observations suggest the inter-relationship between TTP and pregnancy, and point to some pathophysiological aspects of the foetal deth repeteadly presented by one of the patients. A review of the literature is presented on the basis of these cases of PTT associated to pregnancy.