4.7 - Obstetric Cholestasis - Intrahepatic cholestasis of pregnancy

Question 1

Define Obstetric Cholestasis
Explain the pathophysiology

Answer 1

Intrahepatic cholestasis of pregnancy due to the cholestatic effect of oestrogen characterized by
1) Presentation in 3rd trimester of pregnancy, resolving post-partum.
2) Pruritis without a rash!
3) Elevated Bile acids +/- LFTs
Cholestatic effect of oestrogen leads to the accumulation of bile acids which can pass through the placenta leading to sudden intrauterine death

Question 2

What are the risk factors for obstetric cholestasis?

Answer 2

Multiple births
Viral hepatitis
South-asian ethnicity

Question 3

What’re the complications of obstetric cholestasis?

Answer 3

1) Preterm birth
2) Stillbirth
3) Post-partum haemorrhage

Question 4

Why is post-partum haemorrhage a complication of obstetric cholestasis

Answer 4

Liver disease causing reduced vitamin K leading to increased risk of bleeding

Question 5

A patient presents with obstetric cholestasis. Give 6 differential diagnoses and how to rule them out

Answer 5

Itch Ddx:
1) Atopic dermatitis: Hx of atopic dermatitis
2) Allergy: Hx of exposure
3) Puritis Gravidarum: Normal LFTs
4) Pre-existing liver disease: Onset

Hepatic impairment Ddx:
1) Gallstones: RUQ/Epigastric pain, Pale stool and dark urine, Murphy’s sign
2) !!Acute Fatty Liver of Pregnancy: Emergency: Nausea, vomiting, pain, polyuria. a/w hypoglycemia, pre-eclampsia, and DIC
3) HELLP: Reduced Hb, Low platelets, HTN
4) Viral Hepatitis: Viral screen

Question 6

What is the typical presentation and examination findings in obstetric cholestasis

Answer 6

3rd trimester
Pruritis especially on the palms and soles of feet, worse at night
Rare: pale stools, dark urine

Examination: No rash, excoriation marks

Question 7

What is important to elicit in a hx of obstetric cholestasis

Answer 7

Hx of PC: absence of rash, site of itch, exacerbating factors +! Change in products, clothes, medications
Obs Hx: Hx of obstetric cholestasis
Past med: Gallstones/gallbladder disease, hx of atopy, itch, liver disease, renal disease
Fam hx: Liver disease, obstetric cholestasis
Medications: new meds
Social: Alcohol use (fatty liver disease)

Question 8

What investigations would you conduct? (obstetric cholestasis)

Answer 8

Labs:
1) LFTs - Bile acids raised +/- LFTs
2) FBC - rule out HELLP
3) Viral liver screen (rule out hepatitis + CMV and EBV)
4) Autoimmune hep screen
Imaging: Liver US for gallbladder

Question 9

How would you diagnose and manage obstetric cholestasis

Answer 9

Dx: Bile acid levels of 19
Tx:
1) Monitoring: Weekly monitoring of LFTs and Bile acid levels until delivery + close foetal monitoring
2) Topical Emollients (Calamine lotion) + Antihistamines (chlorphenamine)
3) Delivery based on bile acid levels:
19-39 - Delivery at 40 weeks
40-100 - Delivery at 38 weeks
100+ - Delivery at 35-36 weeks
Note: The risk of stillbirth is greater than the general population when >100