Investigations
1st investigations to order
FBC with differential including platelets
Test
Should be performed in all patients with clinical features suspicious of HELLP syndrome.
Anaemia may be present, but because of haemoconcentration, the haematocrit may appear normal.
Thrombocytopenia is present in all patients with HELLP syndrome, owing to increased platelet activation, aggregation, and consumption.
Result
reduced haemoglobin, low or normal haematocrit, thrombocytopenia
peripheral blood smear
Test
Abnormalities are due to haemolysis.
Result
schistocytes, burr cells, polychromasia may be seen secondary to haemolysis and are diagnostic
liver transaminases
Test
Should be performed in all patients with clinical features suspicious of HELLP syndrome.
Abnormalities are secondary to liver dysfunction and periportal necrosis.
Result
aspartate aminotransferase elevated (≥70 IU/L) or alanine aminotransferase elevated (≥70 IU/L), or twice the upper limit of normal concentration
bilirubin level
Test
Increased bilirubin is due to the haemolytic anaemia. The indirect fraction is differentially raised.
Result
increased total and indirect bilirubin
total serum LDH level
Test
Should be performed in all patients with clinical features suspicious of HELLP syndrome.
Elevated levels are due to haemolysis and liver dysfunction.
Result
elevated (>600 IU/L or twice the upper limit of normal concentration)
uric acid level
Test
Should be performed in patients with severe disease who might have evidence of advanced renal compromise, placental abruption, or the suspicion of an imitator disorder.
However, values do not correlate well with disease severity (in contrast to liver transaminase levels or platelet count), and controversy exists regarding the prognostic value of uric acid levels to reflect maternal and/or perinatal risk.
Result
elevated (>356.9 micromol/L [>6 mg/dL])
urinalysis and protein-to-creatinine ratio
Test
Should be performed in all patients with clinical features suspicious of HELLP syndrome.
Proteinuria is caused by increased tubular permeability and is present in 66% to 100% of patients.
Result
proteinuria; protein-to-creatinine ratio of >0.3
PT/PTT
Test
Prolonged prothrombin time/partial thromboplastin time in addition to thrombocytopenia is indicative of progression to disseminated intravascular coagulation.
Should be performed in patients with severe disease who might have evidence of advanced renal compromise, placental abruption, or the suspicion of an imitator disorder.
Result
prolonged
fibrinogen level
Test
Reduced fibrinogen levels (<2.94 micromol/L [<100 mg/dL]) in addition to thrombocytopenia are indicative of progression to disseminated intravascular coagulation. Should be performed in patients with severe disease who might have evidence of advanced renal compromise, placental abruption, or the suspicion of an imitator disorder.
Result
reduced
fetal ultrasound
Test
Should be performed in all patients, to evaluate fetal presentation, gestational age, and biophysical status, and to identify any growth restriction (if fetal growth restriction, progress to Doppler studies of umbilical cord and fetus).
Result
fetal growth restriction
Investigations to consider
serum glucose level
Test
Reduced glucose levels in HELLP may be indicative of liver failure.
Result
hypoglycaemia
serum creatinine and electrolyte levels
Test
Creatinine is increased in cases of associated renal dysfunction; in such cases, significant electrolyte derangements may also be present.
Result
creatinine may be increased; electrolyte disturbances
antithrombin level
Test
Abnormalities develop in advancing disease.
Result
decreased
haptoglobin level
Test
Low haptoglobin levels can confirm haemolysis; rarely performed in practice.
Result
low
maternal upper abdomen ultrasound, CT, or MRI
Test
Should be performed in those patients with significant right upper quadrant or epigastric pain and anaemia.
Result
to rule out significant liver bleeding
lactate dehydrogenase (LDH)-to-aspartate aminotransferase (AST) ratio
Test
Should be calculated to rule out thrombotic thrombocytopenic purpura (TTP).
Result
in HELLP syndrome LDH:AST is <22; TTP LDH:AST is >22
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