Immune thrombocytopenia (ITP) in pregnant women can cause neonatal thrombocytopenia by transport of maternal anti platelet autoantibodies across the placenta. Usually, the infant`s platelet count normalizes within two months. We observed neonatal thrombocytopenia that persisted more than four months and disappeared following discontinuation of breastfeeding. The aim of our study was to discern whether breast-milk of ITP mothers contained anti platelet antibodies causing persistent thrombocytopenia. We collected milk samples from 3 groups of women: ITP - 7 women who had active ITP during the pregnancy, R-ITP – 6 women who had recovered from ITP before the pregnancy and 9 healthy controls. In the milk of ITP patients, we found increased levels of anti platelet antibodies of the immunoglobulin A compare to the other 2 groups. The antibodies bound to αIIbβ3 expressed in cultured cells. Thus, transfer of anti-platelet antibodies from ITP mothers by breastfeeding can be associated with persistent neonatal thrombocytopenia.
