2026 SOAP Annual Meeting

Second-Trimester Abortion Complicated by Atypical Hemolytic Uremic Syndrome (aHUS)

Elizabeth McCarthy, John Markley, Rafa Ifthikhar, Luis Garcia, Eleanor Drey, Pamela Huang, and Maytinee Lilaonitkul

●Pregnancy-associated thrombotic microangiopathies (TMA)

■Microangiopathic hemolytic anemia (Hgb < 10 g/dL, LDH > 1.5 upper limit of normal)

■Thrombocytopenia (<100 x 109 /L)

■End-organ damage

■High morbidity & mortality in aHUS: 4x risk of ESRD and 6x risk of mortality over 10-year period

●Subtypes:

●Case

○24-year-old woman presented for 24-week dilation and evacuation for undesired pregnancy

●Intraop course

○Anesthesia: Deep sedation with paracervical block

○Complicated by post-abortion hemorrhage (EBL 1.7 L) and DIC (Hgb 6.4 g/dL, Plt 89 K/mL, INR 1.7, Fib 65 mg/dL)

○Management

■Intrauterine balloon

■Transfusion: 4 U pRBC, 6 U FFP, 1 U platelet, 5 g fibrinogen concentrate

■Bilateral uterine artery embolization

●ICU postop course

○Rapidly progressive AKI

■Serum creatinine 0.73 mg/dL (pre-op) → 7.62 mg/dL (peak POD4)

○Hematology/nephrology consultations

○DDx: ATN, contrast nephropathy, TMA

○TMA workup

■HELLP, TTP, APLS ruled out

■aHUS

●Equivocal complement genetic panel

●Elevated soluble complement 5b-9 (332 ng/mL)

●Outcome

○Transferred to tertiary care center to initiate eculizumab (complement C5 inhibitor)

○Self-directed discharge before treatment started

○Re-presented on POD11 for SOB

■Diagnosed with new heart failure with mildly reduced ejection fraction (EF 40-45%). DDx peripartum- versus TMA/aHUS-associated cardiomyopathy → started on guideline-directed medical therapy

■Serum creatinine 1.99 g/dL → deferred eculizumab after risk and benefits discussion

●Teaching Points

○aHUS

■Diagnostic challenge due to clinical overlap with other pregnancy-associated TMAs

■Medical emergency with high risk of rapid progression to ESRD

■Early involvement of multidisciplinary specialists

■Prompt treatment with eculizumab improves renal outcomes

○Eculizumab

■Complement (C5) inhibitor

■Appears safe in pregnancy (limited data)

■Plasma exchange if complement inhibitor therapy unavailable

○Optimal management of subsequent pregnancies remains unknown

■Increased risk of recurrence of aHUS or PET

■C5 inhibitor prophylaxis may be warranted in high-risk cases

References:

1.PMID: 22270271

2.PMID: 39156777

3.PMID: 41477157

4.PMID: 28101432

2026 SOAP Annual Meeting

Second Trimester Abortion Complicated by Atypical Hemolytic Uremic Syndrome

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