Pregnancies in kidney transplant recipients with complement gene variant-mediated thrombotic microangiopathy

BACKGROUND: Pregnancies in patients with complement gene variant-mediated thrombotic microangiopathy (cTMA) are challenging, and pregnancies in such patients after kidney transplantation (KTX) are even more so. METHODS: We identified nine pregnancies following KTX of three genetically high-risk cTMA patients enrolled in the Vienna thrombotic microangiopathy cohort. Preventive plasma therapy was used in three pregnancies, and one patient had ongoing eculizumab (ECU) therapy during two pregnancies. RESULTS: Seven out of nine pregnancies (78%) resulted in the delivery of healthy children. The other two included one early abortion at gestational Week 12 during ongoing ECU therapy and one late foetal death at gestational Week 33 + 3, most likely not related to complement dysregulation. Kidney transplant function after delivery remained stable in all but one pregnancy. In the aforementioned case, a severe cTMA flare occurred after delivery despite use of preventive plasma infusions. Kidney graft function could be rescued in this patient by ECU. As such, successful pregnancies can be accomplished in kidney transplant recipients (KTRs) with a history of cTMA. We used preemptive plasma therapy or ongoing ECU treatment in selected cases. CONCLUSIONS: Thus, becoming pregnant can be encouraged in KTRs with native kidney cTMA. Extensive preconception counselling, however, is mandatory in such cases.