Background Information
Definition
ICP is a multifactorial condition that occurs during pregnancy, defined by 2 main characteristics:
- Unexplained pruritus with normal skin appearance
- Abnormal maternal liver function (↑ bile acid)
Aetiology
The pathogenesis of ICP is not fully understood and is considered multifactorial, influenced by both genetic and environmental factors. [Ref]
Risk factors for developing ICP:
- Previous ICP
- Ethnicity (Indian-Asian or Pakistani-Asian origin)
Clinical Features
Most common onset: 3rd trimester
Primary presenting feature: unexplained pruritus + normal skin appearance (i.e. no rashes)
- Excoriation marks possible
- Severity: ranges from mild to unbearable (notably the intensity of itching does NOT correlate with bile acid concentrations)
- Location: palms of the hands and soles of the feet (but often generalised)
- Timing: worse at night (which can disrupt sleep)
Other classic signs of hepatobiliary conditions are classically ABSENT in ICP, including:
- Signs of cholestasis
- Jaundice (very rare – <1%)
- Dark urine and pale stools
- Steatorrhoea (bulky, greasy, foul-smelling stools that are hard to flush)
- Signs of liver failure (e.g. hypoglycaemia, coagulopathy, ascites, hepatic encephalopathy)
Women with ICP are generally clinically well apart from the characteristic itching. If any of the above are mentioned, alternative diagnoses should be considered and excluded.
Complications and Implications
| Category | Complications / implications |
|---|---|
| Maternal risks |
|
| Fetal / perinatal risks | Increased risk of:
|
Diagnosis
There is no single diagnostic test for ICP.
Screening
Women with a history of ICP should have a baseline LFT and bile acid concentration measurement alongside booking blood tests.
Note that this is NOT a routine screening process for the general pregnant population.
Work Up
Standard workup for clinically suspected ICP:
- Total bile acid concentrations
- LFTs
Historically, guidelines recommended extensive testing to rule out other liver diseases, but this is no longer the case for uncomplicated ICP.
The following tests are NOT routinely recommended:
- Liver ultrasound
- Viral hepatitis screen
- Autoimmune screen
- Coagulation test
Additional investigations (e.g. ultrasound, viral hepatitis and autoimmune screen) or referral to a specialist should only be considered if the presentation is atypical, including:
- Onset during 1st and 2nd trimester (typical onset: 3rd trimester)
- Markedly elevated AST / ALT
- Rapidly progressive biochemical picture
- Any clinical features of liver failure, jaundice, or acute infection
- Delayed or absent resolution of symptoms and abnormal blood tests after birth
Diagnostic Criteria
RCOG recommends suspecting ICP in pregnant women with:
- Unexplained itching with normal skin appearance, AND
- ↑ Random total bile acid concentration (>19 mmol/L)
Definitive diagnosis of ICP can only be confirmed postnatally (at least 4 weeks after birth), if:
- Itching has completely resolved
- Bile acid levels have returned to normal
RCOG noted that if the itching and bile acid levels resolved completely DURING pregnancy → ICP is highly unlikely
Women with itching and ↑ ALT or AST but normal bile acid concentrations should NOT be diagnosed with ICP.
Management
Advise women that there is NO available treatment to improve pregnancy outcomes or reduce the raised bile acid concentration.
Pharmacological Management (Symptom Control)
Consider the following to reduce itching:
- Topical emolients (aqueous creams +/- methanol)
- Anti-histamines (e.g. chlorphenamine)
Do NOT routinely offer the following medications:
- Vitamin K – only consider if there is evidence of reduced dietary fat absorption (e.g. steatorrhoea) and/or abnormal prothrombin time
- Ursodeoxycholic acid (UDCA)
- RCOG: do not routinely recommend offering UDCA to prevent adverse perinatal outcomes
- Historically, UDCA was often used in an attempt to improve outcomes and manage symptoms, but recent high-quality evidence has shifted this recommendation
- Studies have demonstrated that UDCA 1) does NOT prevent stillbirth, 2) offers minimal itch relief, and 3) limited and unclear benefits for preterm birth
Timing and Mode of Delivery
Active management of delivery is the primary intervention used to mitigate the risk of stillbirth.
Timing is determined by the ICP severity – the highest recorded bile acid concentration:
| ICP severity | Peak total bile acid concentration (mmol/L) | Timing of planned birth |
|---|---|---|
| Mild | 19-39 | <40 weeks |
| Moderate | 40-99 | 38-39 weeks |
| Severe | ≥100 (highest risk of stillbirth) | 35-36 weeks |
CTGCardiotocography is necessary during labour in women with moderate or severe ICP.
Mode of delivery:
- ICP alone does NOT impact the decision regarding the mode of delivery (i.e. ICP is NOT an indication to offer Caesarean section)
- If planned early birth is indicated, induction of labour is preferred, unless there are other reasons that necessitate a Caesarean birth
Monitoring and Follow-Up
| Monitoring | Recommendations |
|---|---|
| Maternal monitoring | Monitor LFTs and bile acid levels regularly (e.g. weekly in 3rd trimester for moderate ICP)
Women are strongly advised to monitor their baby’s movements (both quality and quantity) and to present immediately to their local maternity unit if they have any concerns or notice a reduction or change in movement |
| Fetal monitoring | The guidelines explicitly noted that fetal ultrasounds and CTGCardiotocography do NOT predict or prevent stillbirths in ICP
CTGCardiotocography is necessary during labour in women with moderate or severe ICP. |
| Postnatal follow-up | Medical review at least 4 weeks after birth should involve:
Women must be advised that they are at increased risk of ICP recurring in any subsequent pregnancies. These patients should have a baseline LFT and bile acid measurement at their booking appointment in future pregnancies. |