Obstetric Cholestasis/AFLP Flashcards
(38 cards)
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.
When to consult a hepatologist?
- If she has severe, very early (T1/T2) or atypical presentation of ICP, because these patients are more likely to have an underlying genetic predisposition or an alternative/additional diagnosis.
- Refer postpartum if the pruritus and biochemical abnormalities fail to resolve.
When does pruritus stop?
Within the first few hours or days for the majority of women.
Post delivery, when are bile acids and LFTs repeated?
4 weeks postpartum.
Lfts may become abnormal during birth and may be elevated in the immediate postpartum period. Testing 4weeks after allows time for the results to normalize.
What are the maternal risks associated with ICP?
1.Pruritus- sleep disruption; negative
impacts on emotional wellbeing and mental health.
2. Preeclampsia- OR:3.7. Ensure ongoing BP assessment and urinalysis at each ANC review.
3. GDM- OR:2.4, however screening follows the recommended guidelines
4. Hepatobiliary disease later in life
5. Immune mediated diseases (DM, thyroid, crowd’s disease + inflamm polyarthritis)
6. Hep C
For an uncomplicated singleton gestation, what are the risk of stillbirth for the following peak bile salt concs?
A. 19-39 micromol/L
B. 40-99 micromo/L
C. 100 micromol/L or more
A. Risk similar to background risk
(0.13%)
B. Risk similar to background risk
until 38-39wks (0.28%) ~0.3%
C. Increased risk (3.44%) ~3%
What are the perinatal risks?
Patients with mod/severe ICP are at higher risks of:
1. Preterm birth (spontaneous/
iatrogenic)
2. MSL during birth and delivery
3. Nursery admission
4. Perinatal morbidity
5. Stillbirth
How often to repeat maternal peak bile acids after diagnosis?
To decide of the timing of delivery, repeat testing is done weekly for both mild ICP (19-39) and mod ICP (40-99).
Severe ICP: future testing may not impact management and MAY not be routinely offered.
What fetal monitoring do you recommend?
As these patients are at increased risk of adverse perinatal outcomes, evaluation includes cardiotocography/non-stress test and obstetric ultrasound for BPP, EFW and dopplers.
- Isolated ICP does not cause FGR, however monitoring for placental insufficiency can be considered in patients who develop preeclampsia or GDM.
- It should be explained to the mother that close fetal monitoring does not predict stillbirth.
- She should be advised to monitor the quality and quantity of her fetal movements and she should present immediately to the maternity unit if any reduction or change in fetal movements is noted.
What medical treatment will you offer?
- Topical emollients such as calamine lotion or aqueous cream with or without 1% menthol.
- Antihistamines (chlorphenamine, diphenhydramine) act as nighttime sedatives.
-Loratidine and cetrizine have no sedative effect and may also be used. - Ursodeoxycholic acid may reduce pruritus in some patients.
- Use of Rifampicin is currently being researched to evaluate use in patients with ICP.
