New research has found that treatment for a liver disorder during pregnancy reduces spontaneous premature birth.

Researchers from King’s College London and Guy’s and St Thomas’ NHS Foundation Trust revealed that ursodeoxycholic acid (UDCA) reduces the risk of spontaneous premature birth (birth before 37 weeks of pregnancy) for women with intrahepatic cholestasis of pregnancy (ICP) by more than 40%. The reduction was particularly significant in women pregnant with a single baby.

ICP is a potentially serious liver disorder that can develop in pregnancy. In ICP, the bile acids do not flow properly from the liver to the gut to help digest food and build up in the body instead. It is known to increase rates of pregnancy complications including premature birth (both spontaneous and clinician-initiated), neonatal unit admission and, for women with the most severe disease, stillbirth.

ICP is the most common liver condition during pregnancy, affecting around 5,500 women each year in the UK. It is most prevalent in South Asian and Latin American women. Spontaneous premature birth affects more than one in 10 women with ICP.

Prevention of premature birth is of considerable benefit, as these babies can be at a higher risk of breathing difficulties, delayed feeding, early childhood death, neurodevelopmental disability and longer term cognitive defects than children born at term.

UDCA is the most commonly used treatment for the management of ICP. Before this research study there was no consensus as to its benefit for women or their babies, with the largest study of its use not reporting benefit.

Primary researcher Dr Caroline Ovadia and collaborators analysed data for over 7,000 women from across the world to explore the benefits of UDCA on ICP in preventing premature and stillbirths. The study also demonstrated that UDCA treatment has the greatest benefit for women with more severe ICP (higher bile acid concentrations), who are therefore at higher risk of spontaneous premature birth.

Lizzie Whitcombe, who was prescribed UDCA during pregnancy, said: “I was 20-weeks pregnant and I was having trouble sleeping and suffering from sleep deprivation. My legs and arms were itching. When I googled my symptoms, I was horrified when I heard about the risk of still birth and meconium staining. I realised I potentially had ICP.

“My doctor prescribed UDCA. It made a real difference to my pregnancy. As soon as I started taking it, I noticed a difference. In a few days my sleep was so much better. I took it through to the end of my pregnancy. Alexander arrived only 10 days early in March.

“Knowing that UDCA reduces the chance of a spontaneous premature birth, it would definitely be something I would choose to take again. You want to be able to carry the baby as long as possible. And the risk of having a premature baby is very stressful. The benefits of carrying baby to full-term are huge.”

Primary researcher Dr Caroline Ovadia, Chadburn clinical lecturer in women’s health at King’s College London, said: “Our research demonstrates that the use of UDCA reduces the rate of spontaneous premature birth for women with ICP. This is an important finding as premature birth can have a severe effect on babies at birth and beyond.

“Therefore, these findings suggest that UDCA should be offered as part of antenatal treatment for women who experience ICP before 36-37 gestational weeks and present with moderate-severe bile acid levels to reduce the risk of spontaneous premature birth.”

Professor Catherine Williamson, professor of women’s health at Kings College London and honorary consultant in obstetric medicine at Guy’s and St Thomas’ and lead researcher said: “It is excellent to discover that UDCA works best for women with more severe ICP, as these women are at greater risk of spontaneous premature birth. We hope our research will inform clinical practice and guidelines, as we’ve found UDCA to be beneficial to women with ICP and their babies.”

Jane Brewin, CEO of Tommy’s which co-funded this research, said: “With 60,000 babies born prematurely in the UK each year, and mothers with ICP facing higher risks, this new study is an important step in making pregnancy safer for vulnerable families. Professor Williamson’s team put this cutting-edge research into practice at Tommy’s specialist pregnancy clinics, but everyone should be entitled to the best possible care for themselves and their babies, so we hope this drug can become widely available to improve support for all those on difficult pregnancy journeys.”

Jenny Chambers, CEO of ICP Support, which also contributed study funding, said: “As a research-based charity, ICP Support welcomes this new finding. We support many women whose babies need additional help in neonatal units because this in itself can cause a lot of anxiety for parents. We believe that having a drug that we know is both safe and reduces the risk of spontaneous premature birth is going to have a huge impact on the wellbeing of both parents and babies.”

The research was funded by Tommy’s, Wellcome Trust, ICP Support and the National Institute for Health Research (NIHR) Biomedical Research Centre at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London.

The Ursodeoxycholic acid in intrahepatic cholestasis of pregnancy: an individual participant data meta-analysis study was published in The Lancet Gastroenterology & Hepatology.