The use of statins may shield unborn babies from their mother's stress, reducing their risk of health problems in later life, scientists believe.

A new study suggests statins, more commonly prescribed to lower high cholesterol, could have a role in protecting the hearts of babies in the womb.

Research by Edinburgh University found the drugs helped counteract the negative impact of stress hormones on fetal growth and heart development in mice.

Normally, babies are protected by an enzyme produced by the placenta that breaks down stress hormones and limits the amount of active hormones that reach the baby's blood supply.

When the expectant mother is stressed, they produce less of this enzyme and the baby is less well protected as stress hormones stop the placenta from developing normal blood vessels.

This cuts back the blood supply to the growing fetus and affects its heart function, meaning it may not grow to full size as a result.

The study, using mice that cannot produce the enzyme, found that statin treatment triggers production of a molecule called VEGF, which stimulates the development of blood vessels in the placenta.

By re-establishing the blood supply, the treatment promotes normal development of the heart and helps the baby to grow to a healthy birth weight.

As well as lowering the chances of babies being born underweight, the therapy could reduce their risk of health problems in later life, including heart disease.

Further studies are needed to assess the long-term effects of statins in pregnancy but the drugs are already used occasionally in pregnant women and should be suitable for clinical trials, according to researchers.

Professor Megan Holmes, of Edinburgh University's British Heart Foundation Centre for Cardiovascular Sciences, said: "These are very exciting results suggesting that there may finally be a potential therapy for women whose placenta is unable to maintain the normal growth of her baby.

"At present there is no treatment and babies may be born prematurely or small, and will be at greater risk of developing cardiovascular disease, diabetes and even psychiatric disorders later in life.

"Although more work needs to be done to show statins are safe in human pregnancy, these results show a new way forward for the major unmet need of fetal growth retardation."

Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said: "Low birth weight has been associated with maternal stress and babies with low birth weights may be more prone to cardiovascular complications later in life.

"In this study, the researchers have discovered that a drug called Pravastatin may counteract the consequences of increased levels of the stress hormone corticosterone within the placentas of mice.

"How Pravastatin counteracts the stress hormone is not yet understood, therefore more research is needed to see whether the drug will have the same effect in humans."

The study is published in the journal Proceedings of the National Academy of Sciences and was funded by the Wellcome Trust.

The research also received funding from the Raine Medical Research Foundation, University of Western Australia.