Obstetric Cholestasis/AFLP Flashcards
Prevalence of OC?
0.7% of all pregnancies
1.2%-1.5% women of Indian-Asian or Pakistani-Asian descent
Aetiology of OC?
The cause is multifactorial and believed to have a genetic and environmental component.
Definition of OC?
OC refers to pruritus in the absence of a primary skin condition with abnormal maternal bile acid concentrations.
Pruritus and raised bile acid concentrations should return to normal after birth.
In patients with OC/ICP, which tests are associated with the risk of stillbirth?
Only the maternal bile acid concentrations are associated with the risk of stillbirth.
Are maternal bile salts associated with the intensity of pruritus?
No
There is no correlation between maternal pruritus and biochemical derangement.
True/False. Pregnant women with normal bile acid concentrations, raised transaminases and pruritus can be diagnosed with OC?
False. The current consensus, according to the greentop guidelines, is that the diagnosis of ICP requires elevated maternal bile acid concentrations.
What’s the diagnosis: pruritus in pregnancy with peak bile acid conc <19micromol/L?
Gestational pruritis
Basically a normal bile acid conc + pruritus
What’s the diagnosis: pruritus in pregnancy with peak bile acid conc 19-39 micromol/L?
Mild ICP
What’s the diagnosis: pruritus in pregnancy with peak bile acid conc 40-99 micromol/L?
Moderate ICP
What’s the diagnosis: pruritus in pregnancy with peak bile acid conc same/greater than 100 micromol/L?
Severe ICP
What’s the upper limit of normal for bile acid conc in pregnancy?
18
What are the clinical concerns/issues with ICP?
- The mother being able to cope with the itching, which can range from mild to unbearable, localized to widespread and can interfere with sleep. This can have a negative impact on her mental health.
- Options available to control the maternal symptoms e.g. pruritus
- Options for monitoring
- Reducing the fetal risks
- Preterm birth
- Anxiety and difficulty sleeping
- The optimal timing of birth
Diagnosis of ICP?
Pruritus in pregnant women with normal appearing skin and a raised peak bile salt conc of 19 micromol/L and above.
- The diagnosis is more likely if confirmed by resolution of the pruritus and elevated bile salts postpartum.
True/False: ICP may resolve in pregnancy
False. Resolution usu occurs post delivery. If resolution occurs during pregnancy, then a diagnosis of ICP is unlikely.
Workup of a patient with suspected ICP?
As ICP is a diagnosis of exclusion it is important to rule out other differentials, especially if pt has an atypical/ uncertain picture of ICP.
- Serum bile acid concs - most sensitive and specific.
2.LFTs - deranged transaminases
between 2-10 x ULN, elevated bilirubin (Unconj + conj) - PT/PTT- coagulopathy present w/
preeclampsia and liver disease
4.Viral Hepatitis screen (A, B, C)
- CMV and EBV - Autoimmune testing - r/o
autoimmune hepatitis; ANA, anti-smooth muscle antibodies, anti-mitochondrial antibodies (r/o intrahepatic cholestasis). - Liver ultrasound - cirrhosis, structural causes of cholestasis - bile duct dilation, cholelithiasis/choledocholithiasis
*2022 GTG suggests that viral, autoimmune and liver ultrasound are not indicated because the likelihood of identifying viral/autoimmune/structural causes is very low, and did not result in new diagnoses.