The ontogeny of fidgety movements from 4 to 20weeks post-term age in healthy full-term infants.

BACKGROUND: Fidgety movements (FMs) are an early accurate marker for normal development.

AIM: The study assessed the ontogeny of normal FMs from 4 to 20weeks post-term age (PTA).

STUDY DESIGN: Longitudinal prospective study of healthy full-term infants video recorded every second week from birth to 20weeks PTA.

SUBJECTS: 21 full-term newborns were enrolled.

OUTCOME MEASURES: Temporal organization, amplitude, character, predominance in proximal and/or distal parts of the body and the presence of FMs in fingers and wrists were independently scored by three observers.

RESULTS: From 4 to 10weeks PTA, FMs were sporadic, becoming intermittent in 1-2weeks; they occurred in the proximal parts, with larger and jerkier movements in the following period. From 11 to 16weeks PTA FMs became smaller in amplitude and slower in speed, they were present in all body parts and were more continual than before. Rotational movements in wrists and ankles and finger movements with open hands appeared. From 17 to 20weeks PTA, FMs became more discontinuous and disappeared at 18-20weeks PTA.

CONCLUSIONS: Developmental course of FMs was seen between 4 and 20weeks PTA with changes in temporal organization, amplitude, speed and body parts involved. The best time for scoring FMs is between 12 and 16weeks PTA.