HELLP syndrome

HELLP syndrome is a pregnancy-related condition and is an abbreviation for:

• haemolysis
• elevated liver enzymes and 
• low platelets

It is considered a severe and life-threatening form of pre-eclampsia although it can occur without co-existing pre-eclampsia. 

Epidemiology

The estimated incidence is  ~0.5% (range 0.17-0.85%) of live births ⁹. The condition often occurs in the 3^rd trimester of pregnancy (and postpartum ¹³). It tends to present in young primigravid women. 

Clinical presentation

The presentation can be variable and can include malaise, epigastric and/or right upper quadrant pain, and nausea and vomiting. Some may have non-specific viral-like symptoms. Hypertension and proteinuria (classic symptoms of pre-eclampsia) may be absent or slight ⁷. 

Pathology

The etiology and pathophysiology remain incompletely understood with multiple theories ¹²:

• immune-mediated: maternal acute rejection reaction to fetal antigens
• placenta-mediated liver injury
• systemic inflammatory response syndrome in the setting of pre-eclampsia

Histology

On liver histology, there is a combination of deposited fibrin, hemorrhage, and hepatocellular necrosis surrounding portal areas ⁶. 

Radiographic features

General features predominantly involve hepatic sequelae:

• hepatomegaly: especially the right lobe
• hemorrhage, subcapsular hematoma, rupture
• hepatic infarction

Ultrasound

Generally preferred over CT, an ultrasound is usually preferred to avoid ionizing radiation.

CT

The place of CT is mainly to assess for complications. When considering a CT scan the radiologist needs to discuss with the obstetrician regarding radiation risk to fetus from radiation, versus clinical suspicion of complications in order to make a rational judgment. The CT scan may show hepatic complications as described above.

Treatment and prognosis

Management is often supportive. Patients with hepatic rupture +/- intraperitoneal bleeding require immediate surgery or selective hepatic arterial embolization. 

Complications

• disseminated intravascular coagulation: reported to occur in ~30% (range 20-40%) of patients ⁵
• hepatic infarction
• hepatic hematoma
• hepatic rupture
• placental abruption

History and etymology

The condition was originally described by Pritchard et al. in 1954 ³ with the acronym later coined by L Weinstein in 1982 ⁴.