EPO and Cognitive impairment: While a meta-analysis of 5 randomized clinical trials estimated a reduced rate of severe cognitive impairments,12,13 neither the large PENUT trial in the United States14 nor the Swiss EPO Neuroprotection Trial15 found a beneficial effect of prophylactic recombinant human erythropoietin (rhEpo) administered to very preterm infants for their neurodevelopmental outcome at 2 years of age.