Cognitive outcomes of extremely or very preterm infants and associated risk factors

Title: Cognitive outcomes of children born extremely or very preterm and associated risk factors: A meta-analysis and Meta-regression

Increasing preterm birth and survival rates have led to a growing number of children surviving preterm birth. However, despite progress in perinatal care long term morbidity rates have not decreased. Extremely or very preterm (EP/VP) birth (<32 weeks gestation) is particularly associated with cognitive impairment, which can place a significant burden on individuals, families, and society, whilst providing challenges for education and health care professionals. Understanding the contributing factors to cognitive outcomes in this population is key for improving outcomes and infant development following EP/VP birth. This meta-analysis and meta-regression studied cognitive outcomes of children born extremely or very preterm since 1990 and the perinatal and demographic factors predicting cognitive outcomes.

A total of 71 peer reviewed studies reporting intelligence scores were included in the analysis, comprising of 7,752 EP/VP infants and 5,155 controls. Median gestational age was 28.5 weeks and the mean age of assessment ranged from 5 to 20.1 years. Children born extremely or very preterm had a significantly lower IQ compared to controls (0.86-SD lower IQ; 95% CI, -0.94 to -0.78, P< 0.001), which was stable in children born between 1990 and 2008. Multivariate meta-regression analysis with backwards elimination demonstrated that bronchopulmonary dysplasia (BPD) explained 65% of the variance in intelligence across studies. Each percent increase in BPD rate across studies was associated with a 0.01-SD decrease in IQ (0.15 IQ points; P< 0.001).

This robust evidence shows large deficits in intelligence in children born EP/VP, which have not improved between 1990 and 2008 despite advancing perinatal care. This emphasizes that improving outcomes after EP/VP birth remains a major challenge, however lowering the high incidence of BPD may be key to improving long-term cognitive outcomes after EP/VP birth. Potential strategies to manage BPD may include an optimal ventilation strategy and oxygen concentration, anti-inflammatory agents, antioxidant therapy, and adequate nutritional support. In addition, recent evidence points at the potential of stem cell–based therapies as a highly promising treatment for neonatal lung and brain injury.

More information on the publication can be found here