Table 2.
Comparison of clinical features and specific management of preeclampsia with severe features (PES)/HELLP syndrome, DIC, TTP, and C-TMA
| Clinical feature | PES/HELLP | TTP | DIC | C-TMA |
|---|---|---|---|---|
| Incidence (per 105 pregnancies) | 1000 | 1 | 130§ | Unknown. May be similar to TTP |
| Time of occurrence during pregnancy/post partum | By definition, occurs after 20 weeks; more common near term and within 3 days post partum | May occur throughout pregnancy, but most common near term and several weeks post partum | Typically at the time of delivery (independent of gestational age) but can occur in the setting of acute illness | May occur throughout pregnancy, but most common post partum |
| Blood pressure | Typically, >160/110 mm Hg, but could be >140/90 mm Hg | Normal | Normal or hypotensive | High, related to acute kidney injury |
| Neurologic abnormalities | Minor (headache, vision changes). Less common: eclamptic seizures, PRES, stroke | Severe in 30% (transient focal defects, seizure, stroke); minor in 30% | None | Inconsistent, but up to 50% of patients |
| MAHA, thrombocytopenia | Moderate | Severe | Variable | Moderate |
| Kidney injury | Mild | Mild | Mild | Severe |
| Liver function tests: ALT, AST | Markedly increased ALT, AST | Normal or slightly increased | Normal (as long as liver dysfunction is not the driver) | Normal |
| Typical course following delivery | Improvement within 24-36 hours | No improvement within 36 hours | Improvement if driven by obstetric complication | Increasing serum creatinine |
| Specific management | Delivery of infant is curative | Plasma infusion or plasma exchange, immunosuppression if acquired autoimmune TTP suspected | Transfusion support, correction of the underlying cause | Anticomplement agent |
The incidence of preeclampsia with severe features is 1 case/100 pregnancies.3 The incidence of TTP associated with pregnancy is estimated from Oklahoma TTP Registry data. Five patients have had TTP associated with pregnancy during 19 years, 1996-2014. Centers for Disease Control in the US state that in 2013, there were 12 births/1000 population36; the Oklahoma TTP Registry region has a population of approximately 2 × 106. Therefore, the Oklahoma TTP Registry region would have approximately 24 000 births/year, 456 000 births/19 years. Five patients with pregnancy-associated TTP/456,000 births is approximately 1 patient/105 pregnancies.
Overall prevalence is low, but risk is highest in patients with placental abruption and amniotic fluid embolism.
MAHA, microangiopathic hemolytic anemia; PES, preeclampsia with severe feature; PRES, posterior reversible encephalopathy syndrome.