Conclusion
The correlation between the AIMS and the PDMS-2 locomotion subscale at 6-and 12- months PTA, was good to excellent in this group of infants born preterm (gestational age ≤ 32 weeks), in Norway. Also, the consistency between the AIMS and the locomotion subscale at both ages, and the gross motor quotient of the PDMS-2 at 12 months, was substantial. The AIMS and the locomotion subscale of the PDMS-2 were equally good predictors for atypical motor outcomes at 24 months PTA. These findings indicate that the AIMS and the locomotion subscale of the PDM-2, could be used interchangeable when assessing motor development in infants at 6- or 12 months of age.