BackgroundHigh birth weight (HBW) describes fetal birth weight of more than 4000 g. Infants with HBW have a high risk of developing neurological and developmental problems. Until recently, there were no studies in the literature that investigated the quality of spontaneous movements and the integrity of the developing nervous system in infants with HBW. The aims of this study were (1) to describe age-specific detailed early spontaneous movements in infants with HBW and (2) to compare the detailed early spontaneous movements of infants with HBW and normal birth weight (NBW). MethodsTwenty-two infants with HBW (median birth weight = 4190 g) and 22 infants with NBW (median birth weight = 3255 g) were included at 10 to 19 weeks post-term age (median = 13 weeks). All infants were assessed according to General Movement Assessment using three- to five-minute video recordings. Video recordings of each infant were evaluated using Motor Optimality Score for three- to five-month-old infants-Revised score sheet. ResultsMotor Optimality Score-Revised (MOS-R) (P < 0.001), observed postural patterns (P < 0.001), and age-adequate movement repertoire (P = 0.005) were significantly lower in the infants with HBW. Infants with HBW had more aberrant (abnormal or absent) fidgety movements (18%) than those with NBW (0%). ConclusionsThe results of this study demonstrated that the motor repertoire of infants with HBW tended to decrease more than that of those with NBW. To enable the follow-up of progression as a result of these assessments infants in need should be referred to age-adequate early intervention programs.