Touching Lives - September 2004
Brain damage in pre-term babies
Led by Professor David Edwards with Dr Mark Sullivan and Professor Mary Rutherford, a large team of researchers has spent several years studying the effect of bacteria on the unborn baby to better understand the link between infection, early delivery and brain damage.
The study at the Department of Paediatrics at Imperial College School of Medicine, London, had the backing of a large group of parents who agreed to let their premature babies be a part of the research.
One large team
Professor Edwards told Touching Lives, “We think of ourselves as a large team, including the clinicians and scientists but also the parents and children and the people and donors at Action Medical Research, whose funding makes this kind of work possible.
“We have been looking at pre-term babies for many years, but wanted to understand better the relationship between bacteria, infection and brain damage. It was already recognised that infection in the womb could cause early delivery, and while there are probably several factors that can lead to such brain damage, we wanted to see how bacteria causing an ^infection in the womb could impact on brain tissue and result in the lifelong problems that some premature babies face^.”
It was thought that the same bacterial stimulus that can cause early delivery was also damaging some unborn babies. But the team had to look at the very fine details to understand exactly what was going on.
In the course of the three-year study, helped by a grant of £171,000 from Action Medical Research, the team utilised brand new techniques for studying bacteria. They used molecular technology to actually see a bacterium’s genetic make up — thereby identifying bacterial genes to isolate those causing a problem.
Professor Edwards said, “We found that some babies born early had bacteria in their placenta, but had no sign of inflammation or other problems at all. Perhaps their bodies had reacted in a different way, or perhaps some types of bacteria were more harmful than others.”
However, some bacteria can activate the babies’ immune system, and traces of immune cells and ‘activators’ were found in the placenta and blood of some infants. High levels were found in babies with brain damage, suggesting that the brain is sensitive to this immune reaction.
In the search for answers, ^the team found unexpected bacteria that seemed to be linked to severe inflammation and damage^, and will now become the subject of ongoing research. The team has also identified a gene involved in the response to infection that seems to be linked to premature birth.
Another groundbreaking technique was used to scan the brains of tiny premature babies as part of the study. A unique MRI scanner had to be developed and installed in the Intensive Care Unit to study such small patients, but it helped the team understand how specific bacteria could cause brain damage and prematurity.
Professor Edwards said, “In identifying specific bacteria and understanding how babies respond to them, and by understanding how a baby’s brain is affected, we are always thinking about how we might protect delicate brain tissue.
Into the detail
“Part of what the study has also demonstrated to us — and this is nothing new — is the importance of infection control. Bacteria can be harmful, and our studies underline the impact of good infection control.
“We will now go on looking at other aspects of bacterial infection and the effect on pre-term babies in the hope that we can make more progress. It has been a huge team effort, a real example of good collaboration between the doctors, scientists, nurses and the patients themselves.
“It has helped our understanding of the link between bacteria and brain damage in pre-term babies, but we had to get right down into the detail to find what we wanted.”