Acute fatty liver of pregnancy Aboubakr Elnashar

Benha university, Egypt

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Rare

1 in 7000 to 1 in 20,000 pregnancies

Potentially lethal

for both the mother and fetus, especially if

diagnosis is delayed.

Commoner in:

primigravidae (although this predilection is not

as marked as in pre-eclampsia).

An association with

male fetuses (ratio 3:1)

multiple pregnancy (20% of cases).

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Maternal and fetal mortality rate

lower than originally believed

{milder cases are recognised and appropriately

treated}

Maternal mortality:

10% to 20%

Perinatal mortality:

20% to 30%

UK:

maternal mortality rate

2%

perinatal mortality rate

11%.

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CLINICAL FEATURES

Usually presents after 30 w, and often near term

(35–36 w)

Gradual onset of nausea, anorexia and malaise.

Severe vomiting (60%)

Abdominal pain (60%) should alert the clinician to the diagnosis.

Co-existing features mild pre-eclampsia,

but hypertension and proteinuria are usually mild.

Jaundice usually appears within 2w of the onset of symptoms

±Ascites.

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Liver function

3- to 10-fold elevation in transaminase levels

raised alkaline phosphatase.

DIC

90%

often the presenting feature postpartum

± severe.

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Usually: renal impairment.

± fulminant liver failure with hepatic

encephalopathy.

Hypoglycaemia

70%

± severe

± Polyuria and features of diabetes insipidus (DI)

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Pathogenesis

±variant of pre-eclampsia.

A subgroup of women with AFLP and

Haemolysis, Elevated Liver enzymes and Low

Platelets (HELLP) syndrome is heterozygous for

long-chain 3-hydroxy-acylcoenzyme

A dehydrogenase (LCHAD) deficiency, a

disorder of mitochondrial fatty acid oxidation.

These women may succumb to AFLP or HELLP

syndrome when the fetus is homozygous for -

fatty acid oxidation disorders.

The mechanism of hepatocellular damage may

involve the affected fetus producing abnormal

fatty acid metabolites. ABOUBAKR ELNASHAR

Diagnosis

DD:

HELLP syndrome

Profound hypoglycaemia (70%)

Marked hyperuricaemia (which is out of

proportion to the other features of

preeclampsia (90%)

Coagulopathy (90%) in the absence of

thrombocytopenia.

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Radiological evaluation

MRI,CT or US:

± hepatic steatosis, but the liver may appear

normal {fat is microvesicular}

CT:

decreased attenuation {fatty infiltration}.

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Liver biopsy with special stains for fatty change

or electron microscopy:

gold standard for diagnosis.

microvesicular fatty infiltration (steatosis) of

hepatocytes, most prominent in the central

zone, with periportal sparing

little or no inflammation or hepatocellular

necrosis.

not always necessary or practical in the

presence of coagulopathy.

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Management

Expeditious delivery:

improved prognosis for mother and baby.

Multidisciplinary team in an intensive care setting.

Coagulopathy and hypoglycaemia

should be treated aggressively before delivery.

Large amounts of 50% glucose may be needed

to correct the hypoglycaemia

fresh frozen plasma and albumin should be

given as necessary.

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The best markers of severity:

– Prothrombin time

– Glucose

– Acidosis and raised lactate

– Encephalopathy.

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Plasmapheresis

has been used in some cases.

N-acetylcysteine (NAC)

an antioxidant and glutathione precursor,

promotes selective inactivation of free radicals

logical tt in hepatic failure

Multiple system failure:

ventilation and dialysis.

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Fulminant hepatic failure and encephalopathy:

referred urgently to a specialist liver unit.

Orthotopic liver transplantation

1. fulminant hepatic failure

2. irreversible liver failure despite delivery of the

fetus and aggressive supportive care.

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Prompt reversal of the clinical and laboratory

findings:

usually follows delivery and may be very

dramatic

Significant morbidity is common (33%)

severe coagulopathy

need for repeated operations to control pp hge

If the woman survives the initial episode:

complete recovery without long-term liver

damage is the norm.

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Recurrence

Has been described:

liver function should be closely monitored in

subsequent pregnancies.

Particularly likely in

women who are heterozygous for disorders of -

fatty acid oxidation:

screening for LCHAD deficiency:

send a neonatal blood spot for

acylcarnitine analysis using tandem mass

spectrometry.

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Conclusion

Rare, but potentially fatal.

The diagnosis should be considered, and liver

function measured, especially if there is vomiting

and abdominal pain.

Differential diagnosis includes HELLP syndrome.

Liver dysfunction is usually marked with

hypoglycaemia, hyperuricaemia, renal impairment

and coagulopathy.

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The woman is at risk of fulminant hepatic failure

and encephalopathy and may require transfer to a

regional liver unit.

Delivery of the fetus is the correct treatment once

hypoglycaemia, coagulopathy and hypertension

have been controlled.

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