Obstetric cholestasis is also known as intrahepatic cholestasis of pregnancy. Chole- relates to the bile and bile ducts. Stasis refers to inactivity. Obstetric cholestasis is characterised by the reduced outflow of bile acids from the liver. The condition resolves after delivery of the baby.
Obstetric cholestasis is a relatively common complication of pregnancy, occurring in around 1% of pregnant women. It usually develops later in pregnancy (i.e. after 28 weeks), and is thought to be the result of increased oestrogen and progesterone levels. There seems to be a genetic component. It is more common in women of South Asian ethnicity.
Bile acids are produced in the liver from the breakdown of cholesterol. Bile acids flow from liver to the hepatic ducts, past the gallbladder and out of the bile duct to the intestines. In obstetric cholestasis, the outflow of bile acids is reduced, causing them to build up in the blood, resulting in the classic symptoms of itching (pruritis).
Obstetric cholestasis is associated with an increased risk of stillbirth.
Presentation
Obstetric cholestasis typically present later in pregnancy, particularly in the third trimester.
Itching (pruritis) is the main symptom, particularly affecting the palms of the hands and soles of the feet.
Other symptoms are related to cholestasis and outflow obstruction in the bile ducts:
- Fatigue
- Dark urine
- Pale, greasy stools
- Jaundice
Importantly, there is no rash associated with obstetric cholestasis. If a rash is present, an alternative diagnosis should be considered, such as polymorphic eruption of pregnancy or pemphigoid gestationis.
Differential Diagnosis
Other causes of pruritus and deranged LFTs should be excluded, for example:
- Gallstones
- Acute fatty liver
- Autoimmune hepatitis
- Viral hepatitis
Investigations
Women presenting with pruritus should have liver function tests and bile acids checked.
Obstetric cholestasis will cause:
- Abnormal liver function tests (LFTs), mainly ALT, AST and GGT
- Raised bile acids
TOM TIP: It is normal for alkaline phosphatase (ALP) to increase in pregnancy. This is because the placenta produces ALP. A rise in ALP without other abnormal LFT results is usually due to placental production of ALP, rather than liver pathology.
Management
Symptoms of itching can be managed with:
- Emollients (i.e. calamine lotion) to soothe the skin
- Antihistamines (e.g. chlorphenamine) can help sleeping (but does not improve itching)
Additional monitoring (including bile acids and LFTs) may be required on an individual basis.
Water-soluble vitamin K may be considered if clotting (prothrombin time) is deranged. Vitamin K is a fat-soluble vitamin. Bile acids are important in the absorption of fat-soluble vitamins in the intestines. A lack of bile acids can lead to vitamin K deficiency. Vitamin K is an important part of the clotting system, and deficiency can lead to impaired clotting of blood.
Planned delivery may be considered, particularly when the LFTs and bile acids are severely deranged. Stillbirth in obstetric cholestasis is difficult to predict, and early delivery aims to reduce the risk.
Last updated September 2020