Objectives: This study describes sleep patterns for mothers and fathers after the birth of their first child and compares exclusive breast-feeding families with parents who used supplementation during the evening or night at 3 months postpartum.
Methods: As part of a randomized clinical trial, the study utilized infant feeding and sleep data at 3 months postpartum from 133 new mothers and fathers. Infant feeding type (breast milk or formula) was determined from parent diaries. Sleep was measured objectively using wrist actigraphy and subjectively using diaries. Lee's General Sleep Disturbance Scale was used to estimate perceived sleep disturbance.
Results: 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.
Conclusions: Parents who supplement their infant feeding with formula under the impression that they will get more sleep should be encouraged to continue breast-feeding because sleep loss of more than 30 minutes each night can begin to affect daytime functioning, particularly in those parents who return to work.