Bile acid levels increases the risk of poor outcomes of pregnancies with intrahepatic cholestasis of pregnancy (ICP)

Our researchers have looked at information from over 5,500 women with ICP and have found that the babies of women with extremely high bile acid levels are most at risk of stillbirth.
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    Professor Catherine Williamson, Dr Caroline Ovadia, Mr Paul Seed, Professor Lucy Chappell

This study is now complete. 

Intrahepatic cholestasis of pregnancy (ICP), also known as obstetric cholestasis, is a rare liver disorder that can develop during pregnancy. It affects around 1 in 140 pregnancies in the UK.

ICP happens when chemicals made by the liver – bile acids – leak into a woman’s bloodstream.The main symptom is itching, which is not harmful but can be very difficult to live with.

ICP can also increase the risks for the baby, with higher chances of premature birth and stillbirth.

No cure for ICP

There is no cure for ICP but ursodeoxycholic acid (UDCA) is often prescribed. This sometimes improves the itching and reduces bile acid levels, and researchers are working to find out whether it helps to protect the baby.

Women with ICP are monitored closely, and may need to be induced early if there is any concern about the wellbeing of their baby. However, babies that are born too soon sometimes need extra support – for example to help with their breathing – and so it is important that we understand more about which babies are most at risk of complications such as stillbirth.

Which babies are more at risk?

To find out more, we combined individual patient data and data from published studies to see whether the severity of ICP – determined by the amount of bile acids in blood – was linked to the likelihood of poor outcomes for the baby.

We analysed information from over 5,500 women with ICP and over 165,000 women with uncomplicated pregnancies.

ICP means higher likelihood of poor outcomes

We confirmed that the babies of women with ICP were more likely to have poor outcomes, including premature birth and breathing problems due to passing meconium (first poo) during pregnancy or labour, and were more likely to be admitted to a neonatal intensive care unit.

Women with extremely high levels of bile acids in their blood (³100 mmol/L) were much more likely to suffer a stillbirth than women with lower bile acid levels.

We will next use a similar approach to find out whether treatment with UDCA during pregnancy can lower the risk of poor outcomes, including stillbirth, for the babies of mothers with ICP.