27 May 2005

500 Scottish mothers and children sought for new study

Researchers at the University of Dundee are seeking 500 Scottish mothers and their children, all of whom were patients at Neonatal units around the country during the years 1999 to 2001.

Scientists at Dundee are working on a new research project into the effects of thyroid hormone in fetal and neonatal life on subsequent brain development as measured by neurodevelopmental outcome.

A less than adequate supply of thyroid hormone (thyroxine) during this critical phase of life can lead to severe and persistent effects with reductions in IQ and cerebral palsy.

The 500 mother-infant pairs were recruited for the past study but researchers need to track them down again for this new project, which aims to give the most detailed results yet on the effects of low levels of thyroxine.

"The new study we have embarked on aims to find out exactly what effect low levels of thyroxine have and how they affect the development of the brain and the part they might play in the onset of cerebral palsy and other conditions," said Professor Robert Hume, Consultant Paediatrician at Ninewells Hospital and Medical School, Dundee.

"Recent studies in Europe and the USA have linked low plasma thyroxine levels in preterm infants with such brain deficits. However, preterm infants are vulnerable to brain damage by various adverse factors before and after birth, not only low thyroxine levels. It is essential that these factors, or confounding variables, be taken into account in follow-up studies, which link low plasma thyroxine levels in preterm infants to IQ and cerebral palsy, and not all studies have done this."

The risk of a low plasma thyroxine level after birth in preterm infants is related to gestational age and is common in infants less than 30 weeks gestation but some infants up to 34 weeks gestation are also still vulnerable. There have been clinical trials of thyroxine supplementation to extreme preterm infants but these were not conclusive and suggested that this treatment was beneficial in very preterm infants (less than 27 weeks) whereas infants 28-30 weeks had a poorer outcome.

"It is clear that the relationship of a low plasma thyroxine level in a preterm infant to brain development is complex and has not been solved," said Dr Fiona Williams, Senior Lecturer, Division of Community Health Sciences at the University of Dundee.

"In order to re-evaluate this problem we have started again. With the efforts of 11 Scottish Neonatal Units, we had previously recruited around 500 infant-mother pairs less than 34 weeks gestation. A wide range of pregnancy, delivery and postnatal data were collected. In addition serum was collected from mothers and infants at birth, 7, 14 and 28 postnatal days and a wide range of thyroid hormones determined. This combination of an extensive background data set and the sera levels of thyroid hormones gives us the largest series dedicated to this problem in the world.

"Now we need to find those mothers and infants again so that we can see how they have developed at five-and-a-half years and what effects levels of neonatal thyroid hormones may have had."

This information is essential for the development of any potential therapies, if indeed they are required.

The origins of this current project have been funded previously by the Scottish Executive Chief Scientist Office and European Commission with the University of Dundee acting as the lead centre for this European project.

This follow-up study is about to begin with combined funding (£300,000) from The Scottish Executive Chief Scientist's Office, Cerebra, Tenovus(Scotland), NHS Tayside and Paediatric Metabolic fund. This study is also led by the University of Dundee with collaboration throughout Scotland, and with the Netherlands and Spain.

NOTES TO EDITORS.

Cerebra is a national charity with an administrative headquarters in Carmarthen, West Wales, telephone 01267-244200, www.cerebra.org.uk and a fundraising call centre in Bristol. Cerebra is concerned with brain injury in children. The charity raises money to fund ground breaking research into brain injury and other neurological disorders in children.

Cerebra also act as a catalyst to provide interaction between professional research and the insight of parents and carers. Cerebra have a specialist information base built up over ten years and ensure that information flows productively between researchers and parents, with all feedback disseminated effectively to produce real outcomes on the ground for affected families and their children.

By Roddy Isles, Head of Press 01382 344910, out of hours: 07968298585, r.isles@dundee.ac.uk