Recent topics in fetal behavioral assessment

Many fetal behaviors are thought to indicate neurological development and may be useful for predicting neurodevelopmental outcomes after birth. In the present article, we review recent fetal behavioral studies focused on early spontaneous movements, eye movements (EMs), regular mouthing movements (RMMs), expression, and our own evaluation method of fetal brain dysfunction. Early spontaneous movement is one of the earliest expressions of neural activity. Changes in fetal EMs are thought to reflect the development of fetal sleep, while RMMs may reflect the development of non-rapid EM sleep. Fetal facial expressions, which may reflect higher brain function, can now be observed in more detail using four-dimensional ultrasound. Furthermore, we propose that assessing fetal brain function by combining multiple behavioral indicators may predict long-term neurodevelopmental outcomes after birth.