Given that CTG monitoring hasn’t been proven to do what it was intended to do, people have been searching for alternative approaches to monitoring the fetus during labour. (Yay!) Given that one of the key goals of fetal monitoring in labour is to predict, with a view to preventing, brain injury, some researchers have focussed on ways to directly monitor the function of the fetal brain.
Researchers from the UK and Slovenia have recently published a “proof of principle” paper (Mires, et al., 2022) about using electroencephalography (EEG) as a form of fetal monitoring. EEG records electrical activity in the brain. The technique is used in neonatal care to help decide who to offer therapeutic cooling to, and to determine the cause of neonatal seizures. In theory at least, it should be possible to record fetal EEG signals using existing fetal spiral electrodes.
This study set out to see whether this was possible. Researchers applied two fetal spiral electrodes to the scalps of 18 healthy adult volunteers (brave souls!), having modified the loose ends of the electrodes so they could be connected to an existing EEG system. Later experiments involved modifications to the leg plate normally used to connect the fetal spiral electrode to a CTG machine. Researchers were able to obtain an EEG signal through the fetal spiral electrode similar to the “gold standard” EEG equipment.
(Sadly, they didn’t provide information on what it felt like to have a fetal spiral electrode screwed into your scalp as an adult. I would like to know this without having to volunteer to try it out myself!)
There are a lot of steps along the way to developing a new technology for healthcare use. Designing a sensor that is acceptable to birthing women and clinicians, demonstrating that a reliable and meaningful fetal signal can be recorded, assessing the safety of the EEG electrode(s) is challenging enough. To then undertake the research required to understand the physiology of EEG changes during labour and their relationship with short- and long-term perinatal outcomes would be quite the job. Only when all these steps have been achieved would it be possible to then attempt to address the question of whether using a fetal EEG monitor in labour might improve perinatal outcomes and what the risks of using it would be.
I wonder whether further work on this system will be done. Will a product end up being brought to market before it is adequately assessed – as was the case for CTG monitoring? Time will tell!
Mires, S., Kerr, R. S., Denbow, M., Dahnoun, N., Tancock, S., Osredkar, D., & Chakkarapani, E. (2022, Jun 21). Foetal amplitude-integrated electroencephalography: proof of principle of a novel foetal monitoring technique in adult volunteers. Journal of Obstetrics & Gynaecology, in press, 1-8. https://doi.org/10.1080/01443615.2022.2081797