Thrombotic Thrombocytopenic Purpura and Atypical Hemolytic Uremic Syndrome Microangiopathy in Pregnancy.

Thrombotic thrombocytopenic purpura (TTP) and atypical hemolytic uremic syndrome (aHUS) are thrombotic microangiopathies (TMAs) that can present in pregnancy. The presentation can be with typical microangiopathic features and thrombocytopenia, but there is also a significant risk of in-utero fetal loss. TTP presents most commonly in the third trimester and aHUS in the postpartum period. On presumptive diagnosis, plasma exchange should be started and ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) activity measured. An activity of < 10% is in keeping with TTP, which may be late-onset congenital TTP or acquired disease: the former will require regular plasma therapy and the latter immunosuppression. In aHUS, eculizumab is the therapy of choice. In future pregnancies, follow-up with a multidisciplinary team including fetomaternal and specialist obstetrics should be undertaken.