iTTP is much more common than cTTP among adults. Although cTTP is less common, many patients may be undiagnosed.

Although it seems probable that there are symptomatic episodes of cTTP in fetuses, there are currently no published reports of this.

Nearly half of newborn infants with cTTP have severe hyperbilirubinemia, anemia, and thrombocytopenia.

Currently, it seems that all women with cTTP have complications during pregnancy. This may be because asymptomatic pregnant women with cTTP have not been diagnosed and published.