Fetal behavioral and psychoneurological development

In this chapter, we focus on the assessment of the integrity and activity of the fetal central nervous system (CNS). Therefore it is necessary to understand normal behavior and which variables can be used to assess that (e.g., eye and body movements). Furthermore, one needs to understand the (neuro)developmental pathway during gestation, as a "younger" fetus shows different behavior compared to the "older" fetus. Behavioral states or sleep states are present at the end of gestation, and even wakefulness occurs independent of birth. These states are defined on the basis of three state criteria: cardiotocographic pattern, presence or absence of body, and eye movements. As in neonatal life, we would like to "test" the CNS, rather than make observations of behavior alone, but we are limited. The intercostal-tophrenic inhibitory reflex is explained as well as fetal habituation as a measure for fetal memory. We conclude that it still remains difficult to perform a prenatal neurologic examination. It is quite likely that no single, isolated aspect of behavior alone will evolve to conduct a fetal neurologic investigation, but rather a combination of (behavioral) tests.