Neonatal and maternal thrombocytopenia: incidence and immune background

We performed a prospective study on the incidence of thrombocytopenia (t-pe nia) and its immunological origin in unselected 26,275 mothers and 24,101 n ewborns. Platelet antibodies were examined by the platelet immunofluorescen ce test (PIFT) and the monoclonal antibody immobilisation of platelet antig ens assay (MAIPA). T-penia (platelet count < 100 x 10(9)/l) was found in 12 4 (0.5%) mothers (in 0.04% severe, <50 x 10(9)/l) and in 116 (0.5%) newborn s (in 0.15% severe); 90 (72.6%) and 112 (96.6%), respectively, were availab le for further studies. In both groups non-immune t-penia was diagnosed abo ut 4.5 times more often than the immune t-penia. Among 90 mothers, t-penia was severe in 11.1%, antibodies were detected in 17.8%; both factors were n ot prognostic for delivering thrombocytopenic newborns. Among 112 babies, 2 1 were delivered by thrombocytopenic mothers and 91 fry mothers with normal platelet count; among newborns with immune t-penia the proportion of alloi mmune (NAIT) to autoimmune was equal(10 with NAIT, 10 with autoimmune, 4 of them born by mothers with hidden autoimmune t-penia). In 33% of the neonat es t-penia was severe, most often among NAIT. In conclusion, although t-pen ia in mothers as well as in infants is not frequent and severe, and an immu ne origin not often found, the search for antibodies, in particular alloant ibodies, should be done. Even if the serological results are not helpful at the moment, they can Be of importance in subsequent pregnancy and for rela ted pregnant women.