Obstetric Cholestasis Flashcards
What is obstetric cholestasis?
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.
How common is obstetric cholestasis?
Obstetric cholestasis is a relatively common complication of pregnancy, occurring in around 1% of pregnant women.
When does obstetric cholestasis usually develop?
It usually develops later in pregnancy (i.e. after 28 weeks).
Briefly describe the pathophysiology of obstetric cholestasis
It is thought to be the result of increased oestrogen and progesterone levels.
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).
Who does obstetric cholestasis commonly affect?
There seems to be a genetic component. It is more common in women of South Asian ethnicity.
What risk is associated with obstetric cholestasis?
Obstetric cholestasis is associated with an increased risk of stillbirth.
How does obstetric cholestasis present?
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.
Importantly, there is no rash associated with obstetric cholestasis. If a rash is present what is the alternative diagnosis?
If a rash is present, an alternative diagnosis should be considered, such as polymorphic eruption of pregnancy or pemphigoid gestationis.
What differentials should be considered for obstetric cholestasis?
Other causes of pruritus and deranged LFTs should be excluded, for example:
- Gallstones
- Acute fatty liver
- Autoimmune hepatitis
- Viral hepatitis
What investigations should be ordered for obstetric cholestasis?
Women presenting with pruritus should have liver function tests and bile acids checked.
How will LFTs and bile acids be affected in obstetric cholestasis?
Obstetric cholestasis will cause:
- Abnormal liver function tests (LFTs), mainly ALT, AST and GGT
- Raised bile acids
Why does alkaline phosphatase (ALP) tend to increase in pregnancy?
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.
Briefly describe the management of obstetric cholestasis
Ursodeoxycholic acid is the primary treatment for obstetric cholestasis. It improves LFTs, bile acids and symptoms.
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)
Water-soluble vitamin K can be given if clotting (prothrombin time) is deranged.
Why may vitamin K deficiency occur in obstetric cholestasis?
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.
What monitoring is rquired in obstetric cholestasis?
Monitor of LFTs is required during pregnancy (weekly) and after delivery (after at least ten days), to ensure the condition does not worsen and resolves after birth.
