By Dr Ananya Mandal, MD
Women who develop obstetric cholestasis (also known as intrahepatic cholestasis of pregnancy) manifest with symptoms of intense itching.
Since itching is a normal feature especially towards the end of the pregnancy, ICP may often be missed. However, it is important to diagnose the condition since ICP may lead to harmful effects in the baby. This includes fetal distress at labor (derangements of fetal vital parameters increasing risk of new born complications and death), premature birth (birth before the due date leading to a decreased chances of survival) and even still birth and fetal death.
Diagnosis and initial assessment includes asking questions about previous history of ICP, ruling out other conditions and so forth. 1-5
Previous history of intrahepatic cholestasis of pregnancy (ICP)
All women who have had a previous history of obstetric cholestasis in a previous pregnancy need to be evaluated for ICP carefully in subsequent pregnancies.
Patients who have a family member with a similar condition (commonly a first degree relative like a mother, grandmother or a sister) need careful evaluation.
Some ethnic groups like those of Asian or South American, Scandinavian, Bolivian or from Chile need to be evaluated for itching during pregnancies. These ethnic groups and races are at a higher risk of this condition.
All these high-risk individuals need to be managed by a consultant-led team and should deliver at a hospital.
Ruling out alternative diagnoses
Causes of liver dysfunction apart from ICP including gallstones, hepatitis, viral infections with Epstein Barr virus, cytomegalovirus, hepatitis A, B, C or E, side effects of medications, preeclampsia (high blood pressure and complications of pregnancy) and fatty liver disease of pregnancy need to be rule out before diagnosing ICP.
The skin is also inspected for other skin conditions like eczema or parasitic infestations like scabies that may also lead to itching.
Blood tests for intrahepatic cholestasis of pregnancy (ICP)
An initial test is a routine blood test. This also includes the liver function test. Liver function tests (LFT) looks at levels of bilirubin and enzymes that show the liver health. These include Alkaline phoshphatase, ALT (Alanine transaminase) and AST (aspartate Transaminase), gamma-glutamyltransferase (gamma-GT) etc.
The LFT should be monitored weekly in suspected cases of ICP. In ICP the levels of bilirubin may be infrequently raised but the levels of liver enzymes may be raised. It should be kept in mind that the upper limit of normal levels of liver parameters is 20% lower than non-pregnant levels, throughout pregnancy.
Interpretation of the results should be made accordingly. LFTs may be conducted weekly if normal, or bi-weekly if abnormal. They may be conducted bi-weekly if serum bile acids are increasing, or are ≥40μmol/L.
Coagulation studies for intrahepatic cholestasis of pregnancy (ICP)
Coagulation studies may be prescribed if abnormal LFTs are seen. Prolonged prothrombin times may reflect Vitamin K deficiency. Since Vitamin K is a fat soluble vitamin that requires normal bile functions for absorption there may be vitamin K deficiency.
Ultrasound scan of the liver
An ultrasound scan of the liver may be prescribed. This is the safest diagnostic method that can be prescribed during pregnancies as X rays and CT scans etc. cause a raised risk of radiation exposure to the fetus.
An ultrasound scan helps to look at liver abnormalities and presence of gall bladder stones.
Fetal surveillance and intrahepatic cholestasis of pregnancy (ICP)
Fetal surveillance is performed to check for the fetal wellbeing. This includes a baseline ultrasound scan to detect fetal growth. Cardiotocograph monitoring (CTG) looks at the heart health of the fetus.
Monitoring suspected cases of intrahepatic cholestasis of pregnancy (ICP)
Visits to the doctor or antenatal visits are schedules every second week in suspected cases.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)