Much like fetal and neonatal alloimmune thrombocytopenia (FNAIT), maternal immune thrombocytopenic purpura (ITP) can lead to thrombocytopenia in newborns, according to a recently published study in the Journal of Obstetrics and Gynecology Research.
“ITP incidence is about 0.2% and constitutes 5% of all thrombocytopenia diagnoses in pregnancy,” the authors wrote. ”ITP is the most common cause of thrombocytopenia diagnosis before mid-pregnancy, whereas gestational thrombocytopenia occurs near-term,”
Learn more about FNAIT treatment and care
The authors aimed to assess the impact of maternal ITP on pregnancies. ITP is an autoimmune condition in which the immune system produces antibodies against its own platelets leading to thrombocytopenia.
Researchers compared the pregnancies of 23 mothers with ITP with the pregnancies of 115 mothers without risk factors. Results showed that pregnancies in which the mother had ITP had a higher rate of fetal growth retardation (FGR), preterm delivery, and APGAR scores.
In approximately 17% of pregnancies complicated with ITP, the maternal antiplatelet antibodies crossed the placenta, causing fetal thrombocytopenia. Three newborns with thrombocytopenia required treatment with intravenous immunoglobulin (IVIG). The authors found no correlation between newborn and maternal platelet counts.
None of the newborns with thrombocytopenia suffered an Intracranial hemorrhage, the most severe complication of fetal and neonatal thrombocytopenia; these results correspond with previous studies that report an incidence below 1% in the context of maternal ITP.
Differences between ITP and FNAIT
Although both conditions lead to decreased platelet counts (thrombocytopenia), the mechanisms are quite different.
FNAIT is an alloimmune disease in which the maternal immune system creates antibodies that target fetal platelet antigens inherited from the father. In ITP, on the other hand, maternal autoantibodies target mainly maternal platelets; fetal platelet destruction occurs in a minority of cases.
ITP usually generates more moderate thrombocytopenia in fetuses and newborns than FNAIT. In ITP, the bleeding complications are experienced mainly by the mother, resulting in postpartum hemorrhage and preterm delivery.
“ITP in pregnancy is an important health issue because of the risk of fetal and maternal complications and adverse outcomes,” the authors concluded.
