Influences in the womb on the fetal heart

Heather MacPherson, Sara Rinaldi, Mikolaj Kotts, Sarah Stock, Karen Chapman, Matt Kemp, John Newnham, Alan Jobe

Using steroids during pregnancy may affect how a baby’s heart develops.

This research study is now complete

Premature birth can affect a baby into adulthood: being born too early can lead to a higher risk of heart disease. We think that this is linked with two things that are often related to preterm birth – inflammation in the womb, and using steroids during pregnancy.

We looked at the hearts of lambs who had been delivered early to mothers who had been given doses of steroids, and compared these to lambs whose mothers had not. The results suggest that steroids may cause a decrease in the growth of heart muscle cells and of the overall density of heart cells in the fetus. These changes occurred in the right ventricle, the part of the heart which is responsible for pumping blood to the lungs to get oxygen.  

Following this research, the next step is to look at how steroids affect the fetus in human pregnancies. Understanding how things that happen before a baby is born can affect how the heart grows is important for finding ways to give babies born early a better chance at a healthy life.



Thanks for your interest in our research

Tommy's funds research across the UK investigating the reasons for pregnancy complications and loss. Maternal and fetal research is underfunded and we need your support to continue. There are many small and large ways you can support us, find out more here.


This study is fully funded by Tommy's and takes place in a Tommy's centre. Tissues were obtained from studies funded by the Bill and Melinda Gates Foundation, GlaxoSmithKline, the Government of Western Australia, the Department of Health and the National Health and Medical Research Council

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