Acute Fatty Liver Disease of Pregnancy

Some women develop a type of fatty liver in the final trimester (last three months) of their pregnancy; this is known as acute fatty liver of pregnancy (AFLP).

AFLP is a very rare condition. It occurs in about 1 in 20,000 pregnancies and is more common in first pregnancies, male babies and twins.
It is not known what causes this pregnancy specific liver condition but some feel it is a variant of pre-eclampsia (raised blood pressure and protein in the urine caused by pregnancy). It has also been linked to an inherited enzyme deficiency called long chain acyl-CoA dehydrogenase (LCHAD) in the baby. LCHAD deficiency is a rare autosomal recessive disorder. This means a gene must be inherited from both parents for an individual to be affected. Often men and women do not know they are a carrier of this changed (mutated) gene, as their bodies are able to continue to metabolise fatty acids normally. However, when both mother and father carry the gene and both genes are passed on to the baby, the baby is then unable to metabolise some fatty acids and a build-up can occur in the womb. The un-metabolised free fatty acids return from the baby, via the placenta, to the mother’s blood stream. This can result in hepatic stress for the mother, causing fat infiltrations to build up in the liver (fatty liver disease).