Yet another reason to breastfeed your baby. This study from 2007 in the Journal of Perinatal and Neonatal Nursing found that:

Parents of infants who were breastfed in the evening and/or at night slept an average of 40-45 minutes more than parents of infants given formula. Parents of infants given formula at night also self-reported more sleep disturbance than parents of infants who were exclusively breast-fed at night.