Haig, David2014-05-062014Haig, David. 2014. “Troubled sleep: Night waking, breastfeeding and parent–offspring conflict.” Evolution, Medicine, and Public Health 2014 (1): 32-39. doi:10.1093/emph/eou005. http://dx.doi.org/10.1093/emph/eou005.2050-6201http://nrs.harvard.edu/urn-3:HUL.InstRepos:12152891Disrupted sleep is probably the most common complaint of parents with a new baby. Night waking increases in the second half of the first year of infant life and is more pronounced for breastfed infants. Sleep-related phenotypes of infants with Prader-Willi and Angelman syndromes suggest that imprinted genes of paternal origin promote greater wakefulness whereas imprinted genes of maternal origin favor more consolidated sleep. All these observations are consistent with a hypothesis that waking at night to suckle is an adaptation of infants to extend their mothers’ lactational amenorrhea, thus delaying the birth of a younger sib and enhancing infant survival.en-USlactational amenorrheainterbirth intervalsnight wakingbreastfeedingco-sleepingevolutionary pediatricsJournal Article2014-05-0610.1093/emph/eou005