Human fetal eye movements: detection in utero by ultrasonography.

Eye movements of the human fetus were detected in utero by means of real-time B-scan and M-mode ultrasonography. In 14 low-risk fetuses studied between 32 weeks menstrual age and term either rapid or slow eye movements or a mixture of both types were detected in 60 +/- 10% (mean +/- SD) of 558 2 min scoring epochs. A comparison of direct echoscopic detection of eye movements in a 3-day-old neonate confirmed that the movements observed in the orbital region with the real-time scanner corresponded well with eye movements seen directly. Thus eye movements can be added to the list of phenomena which can be observed noninvasively for the study of human fetal behaviour.