Preterm infants born at less than 31 weeks' gestation have improved growth in cycled light compared with continuous near darkness

Objectives: Our purpose was to evaluate the benefits of cycled light (CL) versus near darkness (ND) on health in preterm infants born at <31 weeks' gestational age. Study design: Randomized, interventional study comparing infants receiving (1) CL From birth, (2) CL at 32 weeks' postconceptional age (PCA), and (3) CL at 36 weeks' PCA in transition for discharge home. Statistical significance, vas assessed with segmented mixed general linear models, analysis of covariance, general estimating equations, chi(2), and Fisher's exact procedure. Results: Infants receiving CL at birth and 32,weeks' PCA gained weight faster than infants not receiving CL until 36 weeks' PCA. There were no differences among the groups in length of hospitalization stay or number of ventilator days, but the power was low for these variables. Conclusions: These findings suggest that CL has significant weight gain benefits over ND, and there are no short-term advantages of ND over cycled tight for health in preterm infants.