The Early Pregnancy Observational Study (EPOS): following women throughout pregnancy to understand miscarriage

To understand miscarriage better and find ways to predict it, Tommy’s researchers have followed over 1,500 pregnant women throughout pregnancy. They have collected a huge amount of information from these women and are now using this to find ways of predicting the chances of miscarriage.
  • Author's list

    Professor Tom Bourne, Professor Phillip Bennett, Dr David MacIntyre, Dr Maya Al-Memar, Professor Christoph Lees, Dr Hanine Fourie and external collaborators

    Start date: 2016    
    End date: 2024

Why do we need this research?

Up to one in five women will experience a miscarriage in their lifetime and 1% of women will suffer three or more miscarriages. We still don’t know enough about miscarriage, which means that many women do not get an explanation as to why it happened to them or a prediction of the chances of it happening again in the future.

We need better tests to accurately predict the likelihood that a woman will have a miscarriage, whether they’ve had one in the past or not.

What’s happening in this project?

To understand miscarriage better and find ways to predict and prevent it, Tommy’s are supporting The Early Pregnancy Observational Study (EPOS). This study has so far followed more than 1,500 women from five weeks of pregnancy through to birth; 230 of these pregnancies sadly ended in miscarriage.

Our researchers have been looking at donated blood, urine and vaginal swabs from these women to look for bacteria or other substances that could help us understand why miscarriage happens. Samples were collected every two weeks during the first trimester of pregnancy, and then once during each of the second and third trimesters. The team also carried out an ultrasound scan of the baby and collected information about each woman’s clinical history and the outcome of their pregnancy. 

By working with so many women, our researchers have collected a huge amount of data that can be used to find out more about miscarriage. For example, our researchers have already found that women who miscarry during the first trimester are more likely to have lower amounts of a type of bacteria called Lactobacillus in the vagina. They have also found that a hormone called kisspeptin is present in lower levels in women who eventually miscarry. Our researchers have used these, and their other findings, to build two models that can be used to predict how likely it is that a woman will have a miscarriage in the first trimester. They are now asking more women to be involved in the project so that they can check these findings in an even larger group of women. They also plan to carry out a study to find out if treatment with a probiotic can help to prevent miscarriage in women who attend an early pregnancy unit.

As an additional focus, the team are also using data from EPOS to find out more about whether COVID-19 infection during pregnancy can lead to miscarriage or other complications later in pregnancy.

What difference will this project make?

Our researchers believe that EPOS will help them to understand why miscarriage happens. This could lead to problems being detected earlier, enabling healthcare providers to give the best possible care and allowing women and their families to prepare emotionally for the possibility of having a miscarriage. 

Thanks for your interest in our research

Tommy's funds research across the UK investigating the reasons for miscarriage, stillbirth and premature birth. We can keep you updated on ways you can support our work. If you would like to join our fight against baby loss and premature birth, click here.