More aggressive phototherapy may not provide much benefit for extremely low birth weight (ELBW, <1000 g) infants. In a US multicentre trial (New England Journal of Medicine 2008; 359: 1885–96) a total of 1974 ELBW infants were randomised to aggressive or conservative phototherapy. In the aggressive phototherapy group phototherapy was given at a serum bilirubin concentration of 86 μmol per litre (or 120 μmol/ litre for infants in the second week and with a birth weight of 751–1000 g). In the conservative phototherapy group the treatment level was 137 μmol/litre (birthweight 501–750 g) or 171 μmol/litre (birthweight 751–1000 g). Mean peak serum bilirubin concentrations were 120 μmol/ litre (aggressive) vs 168 μmol/ litre (conservative). Death or neurodevelopmental impairment by a corrected age of 18-22 months occurred in 52% (aggressive) vs 55% (conservative), a nonsignificant difference. The rate of neurological impairment was significantly different (26% vs 30%), but among infants with birth weight 501–750 g this was offset by a higher mortality with aggressive phototherapy (39% vs 34%). The authors of this …