Assessment of fetal neurodevelopment via fetal magnetocardiography.

Fetal magnetocardiography (fMCG) offers unique capabilities for assessment of fetal heart rate (FHR) and fetal behavior, which are fundamental aspects of neurodevelopment. The most important attribute of fMCG for FHR monitoring is its high precision, which allows accurate assessment of beat-to-beat fetal heart rate variability (FHRV), including respiratory sinus arrhythmia. Using mathematical indices to assess FHRV, we find that short- and long-term FHRV both increase during gestation but not in the same manner. The largest increases in short-term FHRV occur during the last trimester, while the largest increases in long-term FHRV occur early on, with smaller changes occurring during the last trimester. The fMCG also allows assessment of fetal activity. This results from the high sensitivity of the signal to the position and orientation of the fetal heart. FMCG actograms are therefore specific for fetal trunk movement, which are thought to be more important than isolated extremity movements and other small fetal movements. The ability to assess FHR, FHRV, and fetal trunk movement simultaneously makes fMCG a valuable tool for neurodevelopment research.