Ventricular dilatation in relation to outcome at 2 years of age in very preterm infants: a prospective Finnish cohort study.

Aim: The aim of this study was to analyse the relation between ventricular dilatation at term and neurodevelopmental outcome at 2 years corrected age in infants of very low birthweight (VLBW) or very low gestational age (VLGA).

Method: A total of 225 VLBW or VLGA infants (121 males, 104 female; mean birthweight 1133 g, SD 333 g; mean gestational age 29 wks, SD 2 wks 5d) born in Turku University Hospital were included. Ventricular-brain ratio and the widths of each lateral ventricular horn were determined using ultrasonography, and the volume of the ventricles was measured by magnetic resonance imaging at term. The 2-year outcome measures included scores for the Hammersmith Infant Neurological Examination, the presence of cerebral palsy (CP), the Mental Developmental Index (MDI) of the Bayley Scales of Infant Development (2nd edition), and the presence of severe hearing or vision impairments or any neurodevelopmental impairment (NDI).

Results: CP was diagnosed in 15 participants (6.7%) and severe hearing deficit in 12 participants (5.3%). No severe vision impairment was found. Mild and severe cognitive delay was found in 24 (10.7%) and 8 (3.6%) of the VLBW or VLGA infants respectively. Isolated ventricular dilatation did not increase the risk for developmental impairments. However, ventricular dilatation with additional brain pathology was significantly associated with CP, MDI score below 70, and NDI. A ventricular-brain ratio above 0.35 was a sensitive measure of developmental impairment.

Interpretation: Ventricular dilatation at term increases the risk of poor developmental outcome only when associated with other brain pathology. The ventricular-brain ratio is a useful clinical tool for determining the prognosis in VLBW and VLGA infants.