Table 1

Comparison of typical clinical features and specific management of disorders with microangiopathic hemolytic anemia and thrombocytopenia during pregnancy.

Clinical feature

Preeclampsia/HELLP

TTP

PHUS

CAPS

Incidence

100 in 10,000 pregnancies

1 ​in 10,000 pregnancies

Unknown. May be similar to TTP.

Unknown.

Time of occurrence

By definition, occurs after 20 weeks of gestation; more common near term and within three days postpartum

May occur throughout pregnancy, but most common near term and several weeks postpartum

May occur throughout pregnancy, but most common postpartum

May occur throughout pregnancy, but most common near term and several days postpartum

Vital signs

Hypertension, by definition, BP ​≥ ​160/110mmHg

Normal BP, fever may be present but is rare

Hypertension due to AKI

Multi-organ thrombosis

Neurologic abnormalities

Headache, vision changes. Less commonly eclamptic seizures, stroke.

Severe in 41% (transient focal defects, seizure, stroke); minor in 30%

None

Headache, vision changes, transient focal defects, seizure or stroke

Microangiopathic hemolysis/schistocytes

Moderate

Severe

Moderate

Severe

Kidney injury

Usually mild, but severe AKI is possible. Dialysis is rarely required.

Usually mild or absent; severe AKI requiring dialysis in <5%

Severe, typically dialysis is required

Usually mild, but severe AKI is possible. Dialysis is rarely required.

Liver function tests: ALT, AST

From normal to markedly increased

Normal or slightly increased

Normal

From normal to markedly increased

Typical course following delivery

Stabilization or improvement within 48 hours

No stabilization or improvement within 48 hours

Increasing serum creatinine

Most unchanged, but may improve after delivery

Specific management

Delivery of infant is curative

Plasma exchange, immunosuppression if acquired autoimmune TTP suspected. If hereditary TTP is strongly suspected, plasma infusion is sufficient

Anti-complement agent

Plasma exchange, glucocorticoids, IVIG, anticoagulant

  • PE/HELLP: preeclampsia/hemolysis, elevated liver enzymes, low platelets; TTP: thrombotic thrombocytopenic purpura; PHUS: postpartum hemolytic-uremic syndrome; CAPS: catastrophic antiphospholipid syndrome; AKI: acute kidney injury; IVIG: intravenous immune globulin; ALT: alanine aminotransferase; AST: aspartate aminotransferase.