Fetal movement patterns: a possible means of defining neurologic developmental milestones in utero.

Phased-array ultrasonography provides a means for continuous observation of moving structures. This method can be used for assessing fetal movements from the middle of the first trimester. Eleven separate spontaneous movement patterns were defined in 40 examinations of clinically normal women (6 weeks to term). A trend of increasingly complex movement with advancing gestational age was noted with indication that discrete developmental events such as isolated body extension, thumb sucking, or repetitive chest wall excursions can be recognized. Fetal movement responses to a simple pressure stimulus were noted.