Scientists develop greater accuracy in recording baby’s heart rates in the womb

A team from Imperial College London based at Queen Charlotte’s and Chelsea, Hammersmith and the Royal Brompton Hospitals has worked with equipment developed by scientists at QinetiQ, Europe’s largest science and technology organisation, to study the heart rate of unborn babies in minute detail.

The technique, reported in this months British Journal of Obstetrics and Gynaecology, will allow doctors to monitor the health of babies’ hearts and obtain the full fetal ECG (fECG), particularly during high risk pregnancies, such as where the mother suffers from diabetes or pre-eclampsia or where there is a family history of serious arrhythmia such as Long QT syndrome. These conditions can affect the baby, sometimes resulting in a still birth or sudden death in later life.

Dr Myles J.O. Taylor from Imperial College London and the Hammersmith Hospital comments: “Although it has been possible to record the fECG from the baby in the womb since the 1960’s, the technique has not been totally reliable, as it is difficult to separate the heart rate from background interference. This new technique will allow us to accurately record and analyse the fetal ECG, not just in single pregnancies, but also in multiple pregnancies which we believe is a world first.”

The researchers used electrodes placed on the maternal abdomen to record the data, which are then relayed back to a computer able to process the signals, picking out the baby’s heart signal from background interference, such as from the mother’s heart and external electrical sources.

The equipment uses sophisticated filtering, amplification and signal systems making use of developments in computing and digital signal processing technologies to record this data.

Dr Mark Smith, QinetiQ scientist, who led the team that developed the fECG system, said: “ I am absolutely delighted that the equipment we have developed is getting such excellent results at Queen Charlotte’s.”

The team has studied more than 600 pregnant women so far between fifteen and forty weeks pregnancy including those with twin and triplet pregnancies.

Dr Helena Gardiner, from Imperial College London and the Hammersmith and Royal Brompton Hospitals, adds: “This new technique will be particularly useful in gathering more information about heart function and development in unborn children. Cardiac arrhythmia is believed to be a factor in cot death, and by getting more information on the hearts of unborn babies, it may be possible to detect those at high risk and prevent the devastating effects of some arrhythmias on the fetus and newborn baby.”