Study objectives: To test the hypotheses that: 1) an increase in endogenous progesterone levels during the luteal phase of the menstrual cycle will alter REM sleep and mood state, and 2) a decrease in endogenous progesterone levels during postpartum will also alter REM sleep and mood state.
Design: A longitudinal descriptive study utilizing ambulatory polysomnography for two consecutive nights at seven time points.
Setting: Subject's homes.
Participants: The first hypothesis was tested with 34 women studied during both the follicular and luteal phases of their menstrual cycle. The second hypothesis was tested with 31 women who completed the sleep studies during pregnancy and at one month postpartum.
Interventions: N/A.
Measurements and results: Women who ovulated (high levels of serum progesterone in the luteal phase) had shorter REM latency, more REM sleep, and more positive mood state compared to those who did not ovulate (low luteal progesterone). Compared to the third trimester (high progesterone), REM latency was significantly shorter at one month postpartum (low progesterone). Mood state was most positive at the second trimester and most negative at one month postpartum.
Conclusions: REM sleep and mood state were related to low progesterone levels during the menstrual cycle, but postpartum REM sleep and mood state were related to increased wake time rather than changes in progesterone levels.