AUTOIMMUNE THROMBOCYTOPENIC PURPURA IN PREGNANCY: MATERNAL RISK FACTORS PREDICTIVE OF NEONATAL THROMBOCYTOPENIA

Pregnancy in ATP women is not unusual. The problem of this association concerns the possibility of disease transmission to the fetus due to the crossing of maternal antiplatelet antibodies through the placenta. Maternal risk factors predictive of neonatal thrombocytopenia, can be identified as follows: severe thrombocytopenia, previous splenectomy, high titre of PA-IgG and/or SPB-IgG. In 63 pregnancies in ATP patients, we have evaluated whether the above maternal risk factors, considered in the third trimester, can provide useful criteria for the prediction of neonatal thrombocytopenia. In the third trimester, the distribution of maternal risk factors was as follows: 0 in 7 cases, 1 in 27 cases, 2 in 15 cases, 3 in 12 cases, 4 in 2 cases. From a statistical evaluation, the neonatal platelet values and the maternal risk factors seem inversely correlated (r -0.437; p = 0.0005). In particular, neonatal and maternal platelet count correlated positively (r = 0.249; p = 0.025); moreover, neonatal platelet count correlated negatively with Splenectomy (r = -0.209; p = 0.05), PA-IgG (r = -0.401; p < 0.0005) and SPB-IgG (r = -0.338; p < 0.005). We tried to apply a multiple regression model for all the above parameters which appears statistically significant (p = 0.001); the variability was about 30%. This regression model could be validated if applied to a larger number of cases, and it could represent an alternative to the invasive methods used for the diagnosis of neonatal thrombocytopenia.