We have followed up 63 pregnancies in women with autoimmune thrombocytopenic purpura (ATP). Of these, 15 were previously splenectomized. The characteristics of the sample can be summed up as follows: average age 27 years (17-41); platelets at the beginning of pregnancy, mean 129.5 x 10(9)/l (range 16-488); platelets at delivery, mean 133 x 10(9)/l (range 8-477); PA-IgG at delivery, mean 320 ng IgG/10(7) platelets (range 10-1000); SPB-IgG at delivery, mean 262 ng IgG/10(7) platelets (range 10-1000). There were 30 spontaneous deliveries and 33 cesarean sections. Forty-two newborns had a platelet count within the normal range while nine had a platelet count less than or equal to 150 x 10(9)/l, while six had less than or equal to 100 x 10(9)/l and a further six less than or equal to 50 x 10(9)/l. The aim of this study is the evaluation of maternal risk and of possible feto-neonatal thrombocytopenia at birth. In this regard, the following parameters were considered: previous maternal splenectomy; the platelet count at the beginning of pregnancy; the platelet count and the titres of PA-IgG and SPB-IgG at delivery. Preliminary statistical evaluation of these parameters enabled us to identify a risk score. From this it was possible to obtain an optimum management of the final stage of pregnancy regarding the therapeutic approach and the timing of delivery.