PurposeBecause sleep is essential for normal pregnancy-associated physiological changes and healthy fetal development it is important to provide advice to first trimester expectant mothers in order to enhance self-care. Therefore, the aims of the present study are to clarify first trimester sleep quality and sleepiness characteristics, and to elucidate the affects of stress on sleep and sleepiness characteristics. MethodsSelf-administered questionnaires were distributed to 46 first trimester expectant mothers who were recruited from outpatient departments of two hospitals in Hiroshima, Japan between April 2007 and January 2008. The questionnaire was composed of the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), a sleep log, and the Perceived Stress Scale (PSS). ResultsThe average global score of the PSQI (PSQIG) was 6.67 (±3.20), and 65.2% of participants exceeded the cutoff score. Participants with higher perceived stress had significantly higher PSQIG scores (r=0.38, n=46, p<0.01). There was a positive correlation with PSQIG (r=0.40, n=46, p<0.01) and regularity of bedtime, indicating that participants with well-regulated daily habits have lower PSQIG scores. The average ESS score was 10.1 (±4.3), with 50.0% of participants scoring 11 points or higher. Moreover, primipara had higher scores than multipara (un-paired t (44)=2.52, p <0.05), and those participants with more children had lower scores (r=-0.32, n=46, p<0.05). Sleepiness duration and nap duration were not significantly different for parity. For employment (employed or not-employed), nap duration was significantly different (un-paired t (27)=2.27, p<0.05), however, there was no significant difference in sleepiness duration. ConclusionThis study has shown that first trimester expectant mothers have markedly poor sleep quality and higher levels of sleepiness when compared to women of the same age in the general population. In addition, this study suggests that sleep quality is improved by controlling stress and by having well regulated sleep habits.