Fetal magnetoencephalography (fMEG).

The human brain is one of the most complex organs which develops and adapts continuously over lifetime. Until now, neurophysiological research is mainly related to brain development from birth to adulthood, and neurophysiological research concerning prenatal human brain development only started in the last decades. Magnetoencephalography (MEG) is especially suited for fetal investigation, because it is completely noninvasive and not affected by the biological tissue separating the fetus from the outside. The first successful fetal MEG (fMEG) recording was reported in 1985 (Blum et al. Br J Obstet Gynaecol 92(12):1224-1229, 1985). Since the human brain in utero is highly vulnerable to internal and external influences, prenatal brain research is highly important to understand its development during that time period. Therefore, measurement techniques were improved, and basic research concerning brain development in utero was conducted. So far, mainly auditory and visual stimulation was used to assess fetal brain development by means of changes in signal processing speed or the development of basic forms of learning. The goal of basic fMEG research is to understand healthy fetal brain development and enable an early detection of possible deviations from it. In the future this may allow the development of early, even prenatal treatments and reduce the risk of adverse outcomes. This chapter gives an overview over structural and functional brain development and introduces the fMEG, a measurement technique to noninvasively assess functional fetal brain development in utero. Moreover, current fMEG studies are introduced, and the potential of the method of fMEG is illustrated and discussed