Active head lifting from supine in early infancy: an indicator for non-optimal cognitive outcome in late infancy

Aim: To explore whether active head lifting from supine (AHLS) in early infancy is associated with cognitive outcome in the second year of life.

Method: The presence of AHLS was always recorded in the notes of infants admitted to our tertiary neonatal intensive care unit. Random sampling was used to pair infants with AHLS with two comparison infants without AHLS whose sex, gestational age, birth year (1993-2009), time of assessment, and developmental test (Griffiths Mental Development Scales, Mental Scale of the Bayley Scales of Infant Development-II, or cognitive subtest of the Bayley Scales of Infant and Toddler Development-III) were comparable. Brain injury identified from neonatal cranial ultrasound scans was classified as no - mild or moderate - severe. Z-scores of cognitive test outcomes were calculated for multivariable analysis.

Results: Eighty-seven preterm (34 males, 53 females) and 40 term (17 males, 23 females) infants with AHLS were identified. AHLS was documented at a mean (corrected) age of 7.0 (SD 1.7) and 8.1 (SD 2.2) months respectively. The cognitive assessments were performed at a mean corrected age of 15.7 (SD 1.7) and 23.9 (SD 1.6) months in preterm infants, and 19.1 (SD 2.3) months in term infants. The mean cognitive outcome of preterm and term infants with AHLS was lower than that of infants without AHLS (p=0.002 and p=0.004 respectively). This remained after excluding infants with cerebral palsy with matching comparison infants (p=0.001 in preterm and p=0.001 in term infants). The mean difference was highest (1.35SD) between term male infants and comparison infants (p=0.001).

Interpretation: AHLS is associated with a less favourable cognitive outcome in the second year of life in preterm as well as in term-born infants than in comparison infants.