Abstract
BACKGROUND: Complement-mediated thrombotic microangiopathy (TMA) is a rare endothelial injury syndrome caused by dysregulated activation of the alternative complement pathway, often linked to genetic abnormalities in complement factor H (CFH), complement factor I, or complement factor H-related (CFHR) proteins. Both renal transplantation and pregnancy are independent triggers for recurrence. This case highlights a genetically high-risk patient who achieved a successful term pregnancy after renal transplantation without complement inhibition, emphasizing individualized risk stratification, close surveillance, and multidisciplinary management for favourable maternal and graft outcomes. CASE SUMMARY: A 32-year-old woman with end-stage renal disease secondary to genetically confirmed complement-mediated TMA-homozygous CFH exon 17 deletion and CFHR3-CFHR1 duplication-was maintained on dialysis for 2.5 years before undergoing a successful live-donor kidney transplant from her mother. Post-transplant immunosuppression included tacrolimus, mycophenolate mofetil, and prednisolone, later modified to azathioprine during pregnancy planning. One-year post-transplant, she conceived spontaneously. Pregnancy was complicated by transient gestational hypertension, controlled with nifedipine, labetalol, and amlodipine. Proteinuria remained < 150 mg/day; white blood cell counts 5.8-7.2 × 10(9)/L without cytopenia. Serum creatinine ranged 0.9-1.1 mg/dL, and tacrolimus trough levels 5-7 ng/mL. At 36 weeks, she delivered a healthy 3 kg infant by elective caesarean section. Postpartum follow-up at three months confirmed stable maternal and graft function. CONCLUSION: High-risk complement-mediated TMA patients can achieve successful pregnancy post-transplant through individualized care without mandatory complement blockade.