24 October 2000

Equipment developed by industry and evaluated by University of Queensland researchers may mean safer, more accurate monitoring of the health of a fetus during the birth process.

Monitoring the fetal heart rate is performed during labour in order to identify fetuses at risk of death or brain damage from lack of oxygen to the brain. Fetuses which are at risk can then be delivered urgently.

Conventional methods of fetal assessment are limited by the relative inaccessibility of the fetus, which results in an unnecessarily high rate of operative delivery. A new test being evaluated by Professor Paul Colditz, Professor of Perinatal Medicine at the Royal Women's Hospital in Brisbane, could be the answer.

"Using a new method of fetal monitoring, called fetal intrapartum pulse oximetry, developed by Nellcor (the Tyco takeover is within days of occurring - but unfortunately we need to stick to just Nellcor at the moment), we have conducted important early studies," Professor Colditz said.

"The next step is to conduct a comprehensive evaluation of its efficacy."

Professor Colditz plans to conduct a multicentre, randomised controlled trial at the Royal Women's Hospital in Brisbane, Mater Mothers' Hospital in Brisbane, and Royal Women's Hospital in Melbourne.

Previously cardiotocography (CTG) was the most widely used method of evaluating the status of the fetus. However, several trials have demonstrated severe limitations of CTG, including a doubling of the operative delivery rate with no demonstrated benefit to the baby.

Also, although a normal CTG usually means the fetus is not in distress, an abnormal CTG does not necessarily mean it is in distress.

"A normal fetal heart range is 110 - 160, but a variety of fetal heart rate patterns within and outside that range are difficult to interpret.

"It is possible that the fetus is fine, but it is also possible that the fetus is being deprived of oxygen, which could mean long-term brain damage. That's why a better method of assessing the fetus is essential."

Professor Colditz said monitoring the heart rate leaves a lot of uncertainty, as the
critical factor is really the supply of oxygen to the brain.A fetus normally operates at a very low oxygen level, and until now there was no technology designed to measure this.

"Previously, the only commercially available existing technology measured the top end of the oxygen range such as that of adults," Professor Colditz said.

Professor Colditz said that the new and promising technology of fetal pulse oximetry is best evaluated in a multicentre, randomised controlled trial, rather than just being embraced into clinical practice based on current knowledge.

Full evaluation of the fetal intrapartum pulse oximetry equipment requires funding of over half a million dollars. It has been launched by the generous donation of $30,000 from the Mayne Bequest, a bequest established in 1939 by Dr James O'Neil Mayne and his sister Mary Emelia Mayne to support research initiatives of the University of Queensland School of Medicine.

For more information contact Professor Paul Colditz on 3636 1761 or Peter McCutcheon at UQ Communications on 3365 1088 or 0413 380012 or email: communications@mailbox.uq.edu.au