Fetal magnetoencephalography (MEG), the magnetic signals generated by the developing brain of the human fetus, can be measured with magnetometers placed on the mother’s abdomen. Until recently, only "SQUID" sensors cooled with liquid helium have had the femtoTesla-scale sensitivity to measure these signals. While many neuroscience centers and hospitals have access to SQUID-based MEG systems, nearly all are shaped for adult heads. Due to its high cost, only two worldwide have been capable of fetal MEG, with sensor arrays shaped to accommodate a pregnant abdomen.

However, a recently commercialized quantum sensor, optically pumped magnetometers, is rapidly changing how MEG is done. The sensors operate near room temperature and have the form factor of a Lego brick. This means that the same OPM-MEG systems designed for measuring adult heads can also measure biomagnetic activity elsewhere on the body – and indeed are easily placed on a pregnant woman's abdomen to measure both fetal heart and brain activity. Our group demonstrated for the first time that OPMs can indeed measure fetal brain activity, and we are now working to make OPM-based fetal MEG into a robust technique for assessing fetal brain function. We believe that, with development, OPMs can be used for both prenatal diagnostics in high-risk pregnancies and for developmental neuroscience research.