The favorable outcome of subsequent pregnancy in a patient with a history of obstetric atypical hemolytic uremic syndrome

Abstract

Atypical hemolytic uremic syndrome (aHUS) is a severe life-threatening disease associated with uncontrolled activation of alternative complement pathway. Obstetric aHUS, which develops in pregnant women and puerperas, is characterized by a particularly severe course with multiple organ failure, high death risk and end-stage renal disease. The prognosis of patients with obstetric aHUS has changed dramatically after the introduction of eculizumab, a monoclonal antibody to C5 complement component, into clinical practice. With timely initiation of the complement blocking therapy, the patients would not only survive, but also completely restore the function of the affected organs. Naturally, the question arises on the possibility of repeated pregnancies in women with previous obstetric aHUS and on the strategy of pregnancy management. The paper describes a clinical case of successful treatment with eculizumab for obstetric aHUS in the third trimester of the first pregnancy in a young and previously healthy woman, and the management of her second pregnancy. A 23-year old woman at 35-36 weeks of her first pregnancy developed the clinical picture of obstetric thrombotic microangiopathy, which was interpreted as a manifestation of severe preeclampsia and HELLP syndrome. However, after an emergency surgical delivery, the patient's condition continued to deteriorate despite the plasma exchange procedure. After exclusion of the other causes of thrombotic microangiopathy, aHUS was diagnosed and treatment with eculizumab was started, which resulted in complete recovery. No aHUS-associated mutations were identified. The complement inhibitor treatment was discontinued after 12 months. Four years after the first birth, the patient had a second pregnancy after preconception planning. During pregnancy, the patient was closely monitored for a timely identification of potential complications and had prevention of placental complications with acetylsalicylic acid and low molecular weight heparin. No aHUS recurrence and/or other complications were observed, and the patient did not require treatment with eculizumab during pregnancy. Elective caesarean section was performed at 39 week of gestation. A healthy boy was born with a bodyweight of 3370 g, a height of 50 cm, and Apgar score 8-9. In women with obstetric aHUS history, a favorable outcome of repeated pregnancies is possible, in some cases even without any prophylactic use of complement-blocking therapy, provided that with complete remission of aHUS has been achieved, with close monitoring during gestation and prevention of placenta-associated complications.

Keywords

• obstetric atypical hemolytic uremic syndrome
• eculizumab
• subsequent pregnancy
• preeclampsia prevention