What are the effects of unnecessary treatment with corticosteroids during pregnancy?

Corticosteroids can be used to help a baby’s lungs develop if a woman is at risk of going into labour early. However, they are sometimes used ‘just in case’ in women who actually give birth at term. Our researchers are finding out more about the risks associated with unnecessary corticosteroid treatment during pregnancy.
  • Authors list

    Dr Emily Frier, Professor Rebecca Reynolds, Dr Sarah Stock

    Start date: 2020
    End date: 2022

  • Research centre

  • Research status

    Completed projects

This project took place at our Edinburgh centre which operated between 2008 and 2021.

Why do we need this research?

Corticosteroids are drugs that are given to women who are at risk of going into labour early. They help a baby’s lungs develop, and if given within seven days of birth, can reduce the chances of the baby suffering from lung disease and death – they are most effective when used 24 to 48 hours before delivery. As it can be difficult to predict when a woman will go into labour, some women are given corticosteroids ‘just in case’. However, many of these women will give birth more than seven days after treatment, and some will even give birth at term.

New data suggest that corticosteroid treatment can be harmful to babies who end up being born at early term (37 to 39 weeks) or late preterm (34 to 36 weeks), with their use being linked to low birthweight and an increased likelihood of mental and behavioural disorders in childhood. We urgently need to know more about the risks associated with unnecessary corticosteroid use in pregnancy.

What’s happening in this project?

Researchers funded by Tommy’s are finding out how often corticosteroids are being given unnecessarily during pregnancy. By looking at international birth records from the last 20 years, the team will study the trends in corticosteroid use in different countries. They will check how many women received corticosteroid treatment at any point during pregnancy, but then delivered at term, and how many received corticosteroid treatment at 36 weeks or later.

Our researchers also want to understand more about the risks associated with corticosteroid treatment. By looking at international records relating to 1.9 million births, the team will assess the short-term risks of unnecessary treatment, and by analysing data from 1.1 million births in Scotland, they will find out whether there is a link between corticosteroid use during pregnancy and preschool child health outcomes. They will also look at data from 2,600 pregnancies where corticosteroids were given after 36 weeks, in advance of a planned caesarean section.

What difference will this project make?

This project is expected to show that inappropriate use of corticosteroids during pregnancy can cause unnecessary harm to babies and children. It is hoped that the results of this study will make healthcare professionals and families better able to make an informed decision about whether or not corticosteroids should be used.