Fetal tone is assessed by observing what movement?

Fetal tone is primarily assessed by observing the extension and return to flexion of the fetus. This assessment reflects the neurological and muscular development of the fetus. The ability of a fetus to extend its limbs and then return them to a flexed position demonstrates active muscle tone, which is a key indicator of well-being and neurological health.

Other movements, such as gross body movements, may indicate general activity levels but do not specifically evaluate muscle tone in the same manner. The fetal resting position provides insight into the overall positioning and activity level, but it does not adequately convey the developmental aspect that extension and flexion movements do. Similarly, response to external stimuli can indicate a fetus's awareness and sensitivity but does not directly assess muscle tone. Thus, the movements of extension and return to flexion are the most direct indicators of fetal tone and health.