Impact of low-grade intraventricular hemorrhage on neurodevelopmental outcome in very preterm infants at two years of age

High-grade intraventricular hemorrhage (IVH) in very preterm infants is a known risk factor for adverse neurodevelopmental outcome. Prognosis is less clear for low-grade (grades I/II) IVH however, with conflicting study results in recent years. To evaluate the impact of low-grade IVH on neurodevelopmental outcome at 2 years corrected age in preterm infants born below 32 weeks gestation at the University hospital of Zurich between 2009 and 2014. Among 843 live-born preterm infants born during the observation period, 509 were included in our study. Exclusion criteria were death, high-grade IVH, cystic periventricular leukomalacia and congenital malformations. Infants were grouped into those with or without low-grade IVH according to cranial ultrasound. Neurodevelopmental impairment (NDI) was defined as cognitive or motor developmental score > 2 standard deviations below the mean and/or CP grades 2–5 and/or moderate/severe vision loss and/or hearing problem corrected with hearing aids. Multivariate linear regression was used to assess effect of low-grade IVH on endpoints while adjusting for other risk factors. 87 preterm infants had low-grade IVH (42 grade I, 45 grade II) on cranial ultrasound. These were compared to 422 preterm infants without IVH. Follow-up rate was 82.4 %. Preterm infants with low-grade IVH had higher rates of NDI (21.8 vs 13.3 %, p = 0.047). Infants with IVH grade II had significantly higher rates for CP (8.9 % vs 3.6 %, p = 0.003), visual impairment (20.5 % vs 8.3 %, p = 0.009) and NDI (33.3 % vs 13.3 %, p < 0.001). In our study, low-grade IVH – and especially IVH grade II - is associated with adverse neurodevelopmental outcome at 2 years of corrected age.