Some premature infants are more susceptible to respiratory infections than infants born at term. Babies at greatest risk are those born at less than 32 weeks gestation. What might be a simple cold in other children can become a serious lung infection in these children. This risk is usually higher in winter than in summer and during the first 18 months of a child's life. As these children grow and their immune systems mature, this risk decreases. Consult with your doctor about this risk if your child was born prematurely. Some babies may benefit from treatment that reduces the severity of a common viral infection, respiratory syncytial virus (RSV).