Pregnant women with overweight and obesity (PW-OW/OB) are at elevated risk for sleep disturbances. Scant research has examined the extent to which sleep disturbances are related to pregnancy outcomes. Most studies have used subjective self-report assessments of sleep quality/duration which may be influenced by participant bias; objective assessments may provide a more accurate estimate of sleep outcomes. This study examined if subjective (sleep logs) and objective (activity monitor) measures of sleep outcomes (total nighttime sleep duration, daytime nap duration) were equivalent in PW-OW/OB.
PW-OW/OB (N=14) participating in a 6-week prenatal weight management intervention completed self-report sleep logs and wore an activity monitor (Jawbone) for seven consecutive days at ~16 weeks gestation to measure total nighttime sleep and daytime nap duration. Paired t-tests and equivalency testing was used to compare self-reported and objectively assessed sleep outcomes.
On average, women were 29 years old (SD = 4.5), nulliparous (100%), and OW (57%). There was no difference in total nighttime sleep duration assessed with the monitor (Mmin/night = 435.6) and self-report log (Mmin/night = 447.1; p>.05) or significant associations (r=-.01, p>.05). However, total nap duration was significantly greater when measured by monitor (Mmin/day = 345.8) than self-report (Mmin/day = 38.0); however, they were not significantly associated (r=-.19, p>.05).
These preliminary findings suggest correspondence between self-report and objectively assessed total nighttime sleep duration but not daytime nap duration. One potential explanation is that the activity monitor may not differentiate between nap duration and sedentary behaviors. Also, women may be underreporting their daytime nap duration. Further research is needed to replicate these findings before conclusions can be made about which method provides the most accurate estimate of sleep outcomes in PW-OW/OB.