Hemolytic Uremic Syndrome in Pregnancy and Postpartum

Clin J Am Soc Nephrol. 2017 Aug 7;12(8):1237-1247. doi: 10.2215/CJN.00280117. Epub 2017 Jun 8.


Background: Pregnancy is associated with various forms of thrombotic microangiopathy, including hemolytic uremic syndrome. A previous small French study suggested that pregnancy-associated hemolytic uremic syndrome was to be included in the spectrum of atypical hemolytic uremic syndrome linked to complement alternative pathway dysregulation.

Design, setting, participants, & measurements: We sought to retrospectively analyze the presentation, outcome, and frequency of complement alternative pathway gene variants in a larger international (France, United Kingdom, Italy) cohort of patients with pregnancy-associated hemolytic uremic syndrome.

Results: Eighty-seven patients with pregnancy-associated hemolytic uremic syndrome were included. Hemolytic uremic syndrome occurred mainly during the first pregnancy (58%) and in the postpartum period (76%). At diagnosis, 56 (71%) patients required dialysis. Fifty-six (78%) patients underwent plasma exchanges, 21 (41%) received plasma infusions, and four (5%) received eculizumab. During follow-up (mean duration of 7.2 years), 41 (53%) patients reached ESRD, 15 (19%) had CKD, and 18 (28%) patients experienced hemolytic uremic syndrome relapse. Twenty-four patients (27%) received a kidney transplant and a recurrence of hemolytic uremic syndrome occurred in 13 (54%) patients. Variants in complement genes were detected in 49 (56%) patients, mainly in the CFH (30%) and CFI genes (9%).

Conclusions: Pregnancy-associated hemolytic uremic syndrome and atypical hemolytic uremic syndrome nonrelated to pregnancy have the same severity at onset and during follow-up and the same frequency of complement gene variants.

Keywords: Antibodies, Monoclonal, Humanized; Atypical Hemolytic Uremic Syndrome; Complement Pathway, Alternative; Female; Follow-Up Studies; France; Humans; Italy; Kidney Failure, Chronic; Plasma Exchange; Postpartum Period; Pregnancy; Recurrence; Retrospective Studies; Thrombotic Microangiopathies; United Kingdom; chemotactic factor inactivator; complement; eculizumab; hemolytic uremic syndrome; kidney transplantation; pregnancy; renal dialysis; thrombotic microangiopathy.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Monoclonal, Humanized / therapeutic use
  • Complement Activation / drug effects
  • Complement Activation / genetics
  • Complement Factor H / genetics
  • Complement Factor I / genetics
  • Complement Inactivating Agents / therapeutic use
  • Disease Progression
  • Europe
  • Female
  • Genetic Predisposition to Disease
  • Genetic Variation
  • Hemolytic-Uremic Syndrome / complications
  • Hemolytic-Uremic Syndrome / genetics
  • Hemolytic-Uremic Syndrome / immunology
  • Hemolytic-Uremic Syndrome / therapy
  • Humans
  • Kidney Failure, Chronic / etiology
  • Middle Aged
  • Phenotype
  • Plasma Exchange
  • Postpartum Period*
  • Pregnancy
  • Pregnancy Complications* / genetics
  • Pregnancy Complications* / immunology
  • Pregnancy Complications* / therapy
  • Recurrence
  • Renal Dialysis
  • Renal Insufficiency, Chronic / etiology
  • Retrospective Studies
  • Time Factors
  • Treatment Outcome
  • Young Adult


  • Antibodies, Monoclonal, Humanized
  • CFH protein, human
  • Complement Inactivating Agents
  • Complement Factor H
  • eculizumab
  • CFI protein, human
  • Complement Factor I