Low-grade intraventricular haemorrhage is not as harmless as first thought when born extremely preterm.

Abstract

Intraventricular haemorrhage (IVH) is a known serious complication of preterm birth, especially in extreme preterm infants. IVH pathophysiology is thought to be multifactorial with changes in the germinal matrix, cerebral autoregulation coupled with underlying problems of coagulation and possible genetic issues.1 In this study, the authors looked at IVH and the neurodevelopmental outcomes at 8 years of corrected age. They strengthen the understanding that higher grades of IVH have worse neurodevelopmental outcomes. However, they show data to suggest that lower grades of IVH have an increased risk of cerebral palsy compared with no IVH. This study was designed well, with a large sample size of over 500 infants, and the controls were matched for an expected date of delivery, the child's sex, maternal health insurance status and country of birth. The study was performed in a large centre with good rates of follow-up to 8 years of corrected age in both groups. Even taking into account the good aspects, a few areas were not clear. The term born controls were used to generate IQ and academic performance. However, they were not matched with regard to maternal age and maternal school achievement, which are independent risk factors for poor neurodevelopmental outcomes.2 Also, the controls were difficult to follow during this study, with no results stating the rates of cerebral palsy in the controls compared with extreme preterm infants. The authors also rightly mention the significance of periventricular leukomalacia (PVL) and white matter damage as concerns for neurodevelopmental outcomes.3 However, this confounder was not accounted for in the analysis. In addition, there is no discussion about the impact of bilateral vs unilateral IVH on the outcome. Finally, there was a change in the assessment of cerebral palsy during the study process, but the authors discuss this change. This study has highlighted a few points to consider for future practice. We as clinicians already understand the relationship between grade 3 and grade 4 IVH with worse outcomes, and we counsel parents well on this association.4 This study empathises the worse motor outcomes for grade 3 and grade 4 IVH with 43% and 92%, respectively, for extremely preterm infants having any motor dysfunction. Most clinicians are often reassured when counselling for the lower grades of IVH; however, this and other studies5-7 conclude that grade 1 and grade 2 IVH are independent risk factors for poor neurodevelopmental outcomes with increased risk of cerebral palsy. The main message of this study was to remind clinicians of the higher risk of cerebral palsy at the lower grades of IVH, informing neonatologists that the risk is more than doubled from no IVH to grade 1. This study highlights that lower grades of IVH are not as benign as first thought. At 8 years of life, they have a greater risk of cerebral palsy, more than double the rate, compared with no IVH.8 From these observations, clinicians should be cautious and tentative about sounding optimistic regarding the prognosis of lower grade IVH and should communicate this with families sensitively. None.