Predicting neurodevelopment in very preterm infants using the Test of Infant Motor Performance

Background

Infants born very preterm (VPT) are at increased risk of neurodevelopmental impairments. The Test of Infant Motor Performance (TIMP) is an assessment used to evaluate an infant's gross motor skills, however, understanding of its predictive accuracy in VPT infants is limited.

Aims

To determine the accuracy of the TIMP assessed at term equivalent age (TEA), and 3 months corrected age (CA), to identify motor or cognitive impairment at 12 months CA in VPT infants.

Method

This prospective observational cohort study recruited 202 infants born at <31wks gestational age (GA). At TEA and 3 months CA the TIMP was performed. At 12 months CA the following neurodevelopmental assessments were conducted; Alberta Infant Motor Scale (AIMS), Neurological Sensory Motor Development Assessment (NSMDA) and Bayley Scale of Infant and Toddler Development 3rd edition (Bayley III).

Results

The TIMP had higher specificity than sensitivity across all four outcome measures. Using a cut off-of ≤ -0.5 at TEA, TIMP z-scores demonstrated low sensitivity and specificity for motor outcomes on the NSMDA (sensitivity 61 %, specificity 50 %), AIMS (sensitivity 59 %, specificity 50 %) and Bayley III (sensitivity 56 %, specificity 51 %). Area under the curve analyses showed that the TIMP assessed at 3 months had greater accuracy than at TEA in identifying neurodevelopmental impairments at 12 months CA.

Conclusions

The TIMP assessed at TEA and 3 months CA correctly identified the majority of VPT infants without motor and cognitive impairments. However, it missed VPT infants who developed adverse neurodevelopmental outcomes by 12 months CA.