A prospective study of sleep, mood, and cognitive function in postpartum and nonpostpartum women.

OBJECTIVE: To compare the sleep patterns, mood states, and cognitive functioning of primiparous mothers during the first 3 weeks postpartum with those of a control group of nonpostpartum women and to assess the relationships among these variables.
METHODS: For the first 3 weeks postpartum, 30 primiparous women and 28 nonpostpartum mothers completed daily assessments of mood and recorded multiple aspects of sleep including time of retiring, occurrence and duration of sleep interruption, time of awakening, and morning alertness. Objective measures of memory, attention/concentration, and psychomotor performance were obtained on three occasions.
RESULTS: Postpartum women reported more evening awakenings, more time awake after retiring, and more naps than controls, but overall sleep time was similar. New mothers experienced a higher level of dysphoric mood during the first week than nonpostpartum controls; however, controlling for the effect for "time awake" at night eliminated the significant effect for dysphoric mood. Few differences were observed on the multiple assessments of cognitive function; however, performances of new mothers on memory and psychomotor tasks were likely to be influenced by sleep loss.
CONCLUSION: Women must make important adjustments in their sleep patterns during the postpartum period. In the study group, these adjustments were largely successful, particularly after the first week postpartum, in avoiding the negative consequences of sleep disturbances such as dysphoric mood and impaired cognitive function. Nevertheless, the significant associations between sleep indices and mood and objective measures of cognitive function point to the importance of encouraging appropriate amounts of sleep for recently delivered women.