原 著
*1Osaka University Graduate School of Medicine, Division of Health Science, Doctoral Course *2Osaka University Graduate School of Medicine
*3Kouseiren Hiroshima Hospital
Received 19 March 2008; accepted 4 November 2008
Sleep quality and sleepiness characteristics
in first trimester expectant mothers
Haruko SHINKAWA
*1, Mieko SHIMADA
*2, Terumi FUJITA
*3Abstract Purpose
Because sleep is essential for normal pregnancy-associated physiological changes and healthy fetal develop-ment 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.
Methods
Self-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 ques-tionnaire was composed of the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), a sleep log, and the Perceived Stress Scale (PSS).
Results
The average global score of the PSQI (PSQIG) was 6.67 (±3.20), and 65.2% of participants exceeded the cut-off 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 par-ticipants 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 differ-ence in sleepiness duration.
Conclusion
This 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.
Key words: sleep quality, sleepiness, first trimester, stress
Original article
I. Introduction
When compared to non-expectant mothers, expect-ant mothers exhibit increased nocturnal sleep time and time spent in bed. However, they also have difficulty maintaining sustained sleep, and sleep efficiency is low-ered (Hertz, 1992; Suzuki et al., 1994; Lee et al., 2000). These changes in sleep architecture have been observed
at the initial stages of pregnancy (Hedman et al., 2002; Lee et al., 2000). Moreover, sleep has been shown to be essential for normal pregnancy-associated physiological changes and fetal development because of the increased risk of pregnancy-induced-hypertension (PIH) and a small-for-gestational-age birth in expectant mothers who snore or have sleep-disordered-breathing (SDB) (Loube, 1996; Franklin et al., 2000). Changes in sleep
Sleep quality and sleepiness characteristics in first trimester expectant mothers
pattern and increased daytime sleepiness during the first trimester have also been clinically observed, however, few studies have used standardized scales to evaluate sleepiness or clarify sleepiness time.
Changes in sleep quality and sleepiness architec-ture during pregnancy can be caused by rapid and sig-nificant changes in the expectant mother’s hormonal environment (Lancel et al., 1996). Also, surveys of the general population and the employed have reported that those who have higher stress levels have shorter sleep time (Kim et al., 2000; Nakata et al., 2004), and stronger daytime sleepiness (Kaneita et al., 2005). Studies have suggested that expectant mothers who have poor sleep may have higher stress levels. Particularly during the first trimester, or even when conception is being pur-sued, various stresses are felt due to pregnancy-associat-ed physiological and psychosocial changes, but little is known regarding the relation of stress levels in the first trimester to sleep quality, or sleepiness. Consequently, if we can clarify first trimester sleep quality and sleepiness characteristics and their relationship to stress, we will be able to design enhanced self-care programs for expect-ant mothers that will improve their sleep habits.
Therefore, the aims of the present study are to clar-ify characteristics of sleep quality and sleepiness in the first trimester, and to elucidate the relationship of stress to sleep and sleepiness patterns.
II. Method
1. Participants:
The participants were 51 expectant mothers, with a maximum of 16 weeks gestation, who received medi-cal examinations in the Obstetrics and Gynecology Outpatient Departments of two hospitals in Hiroshima Prefecture, Japan. Participants with hypertension, dia-betes, psychiatric disorders, or other serious medical complications or illnesses, as well as non-native speak-ers of Japanese, were excluded from the study. The investigation period was from April 2007 to January 2008. Volunteers from the nursing staff at each hospi-tal explained the research protocol and data collection process to prospective participants who were present for scheduled medical examinations. After obtaining
partic-ipants’ cooperation and written consent, questionnaires and sleep logs were distributed and collected by return-mail. The questionnaire was composed of the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, the Perceived Stress Scale, and questions concerning de-mographic data. Moreover, participants recorded sleep logs for 3 to 5 weekdays. This study was approved by the Osaka University School of Health Science Ethics Committee (Approved March 2007, #11). Fifty (98.0%) of 51 distributed questionnaires were collected but four participants’ Pittsburgh Sleep Quality Index or sleep logs were rejected because of invalid responses. The re-maining 46 (94.0%) were valid responses and were used in the analysis.
2. Instruments:
1) Pittsburgh Sleep Quality Index
The Pittsburgh Sleep Quality Index (PSQI) was used to evaluate participants’ sleep quality. The PSQI is a widely used standardized scale that evaluates respon-dents previous months sleep quality. The PSQI has been standardized, and its validity and reliability verified for use with Japanese (Doi, et al., 2000). The 18 items of the self-rated PSQI assess sleep quality, sleep duration, sleep onset, sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction, which form seven component scores. The sum of component scores yields a Global score (PSQIG) ranging from 0 to 21, a high score indicating a sleep complaint. A cut-off value of 5.5 points yields optimum sensitivity and speci-ficity in distinguishing sleep disorders (Doi et al., 2000), and is therefore used in our analysis.
2) Epworth Sleepiness Scale
The Epworth Sleepiness Scale (ESS) is a ques-tionnaire that evaluates perceived sleepiness in eight situations commonly encountered in daily life (Johns, 1991). A high score on a 0 to 3 point Likert-scale indi-cates a strong perception of sleepiness during a given daily activity. Because execution is simple, it is fre-quently used as a subjective measurement of Excessive Daytime Sleepiness (EDS). We used Fukuhara et al.’s (2006) JESS modified for Japanese participants, which has been validated and reliability verified, and standard-ized. Total ESS scores range from 0 to 24, with scores
search with Japanese participants (Doi et al., 2000; Doi & Minowa, 2003; Takegami et al., 2005), and therefore we considered a score of 11 points or more as indicative of EDS.
3) Sleep log
Participants kept sleep logs making entries in mornings and evenings for 3 to 5 days, recording times for bedtime, sleep onset, waking time, rising time, times for strongly felt sleepiness and nap time. Participants kept sleep logs for weekdays only in order to clarify differences in sleep habits and sleepiness state between employed and not employed expectant mothers, and to exclude the influence of family weekend behavior on ex-pectant mothers’ sleep habits. The sleep log was adapt-ed from Akimoto et al., (1960) which is widely usadapt-ed in neuropsychology in the diagnosis of sleep states. We verified all log entries visually, and then divided entries into 15 minute intervals which composed the sleep pat-tern. Each participant’s daily entries for time and dura-tion were given a mean value and analyzed. We referred to a study by Shimada et al. (1993) where the standard deviation (SD) of average sleep onset was regarded as regularity of sleep-wakefulness rhythm, and the SD of average bedtime, and average rising time were regarded as regularity of bedtime and rising time, respectively. Moreover, in order to clarify the distribution rate for perceived sleepiness, the number of participants who perceived sleepiness at each interval was divided by the total number of days to give the sleepiness rate.
4) Perceived Stress Scale
We used a Japanese translation (Sumi, 1997) of a ten-item Perceived Stress Scale (PSS) (Cohen & Wil-liamson, 1988) modified from Cohen et al.’s (1983) original. Scores for each of the ten items range from 0 to 4, with a total PSS score range of 0 to 40. A higher score indicates a higher degree of stress perception. The PSS is a standardized assessment that measures the degree to which respondents feel daily-life situations are stressful, and find their lives to be unpredictable, uncontrollable, and overloading. Expectant mothers are not only con-scious of the stress associated with pregnancy, but also conscious of stress arising from daily living. Although
associated with pregnancy and daily life. Therefore, we confirmed content validity of the PSS for use with expectant mothers. The PSS is widely used to evaluate stress during the perinatal period (Hurley et al., 2005; Corwin et al, 2005). In this study, Cronbach’s alpha reli-ability for expectant mothers was 0.80.
3. Analysis:
Statistical Package for Social Sciences (SPSS) ver.16.0L was used for statistical analysis. In a bivariate analysis, we used 2-tailed t-tests to test for significant differences between means for continuous variables such as PSQI, ESS, PSS scores, and sleeping habits. The χ2 test was used to test for significant differences in
categoric variables such as parity and, employed or not employed. Household groups were compared using one-way analysis of variance, and data of pairs of groups were analyzed using Tukey’s multiple comparison.
PSQI scores, ESS scores, sleepiness duration, nap duration, and relationships between variables (age, ges-tation week, BMI, PSS score, sleep habits SD) were assessed using Pearson’s product-moment correlation coefficient.
III. Results
1. Participants
The demographic characteristics of the participants are shown in Table 1.
Perceived stress as indicated by PSS scores ranged from 7 to 38 points, with an average of 20.7 (±5.9) points. There was no significant difference in PSS scores for parity, employment (employed or not-em-ployed), or symptoms of nausea, itching, headache or back pain. Moreover, there was no relationship between PSS scores and age, gestation week, BMI, or number of children (Table 1).
2. PSQI and Sleep Quality
Average PSQIG was high at 6.67 (±3.20) points, with 30 (65.2%) participants exceeding the cut-off of 5.5 points. Component scores are shown in Table 2. No
Sleep quality and sleepiness characteristics in first trimester expectant mothers
participant took sleep medication.
3. Perception of Sleepiness and Naps
The ESS average score was 10.1 (±4.3) points, and 23 (50.0%) participants exhibited EDS. Periods of sleepiness, sleepiness duration, and nap time are shown in Table 3. Periods of sleepiness occurred throughout the day, from immediately after rising until bedtime. Sleepi-ness start times were from 8:15 to 21:30, and sleepiSleepi-ness ending times were from 9:00 to 23:00. Average rising times and bedtimes were 7:18 (±1.58) and 22:94(±1.22),
respectively. Moreover, duration of sleepiness was from 25 minutes to 3 hours, with an average of 72.4 (±33.6) minutes. Figure 1 shows the hourly sleepiness rate. There are two peaks for perception of sleepiness, one at 11:00, and the second from 14:00 to 15:00. More than 10% Table 1 Demographic data and correlation with the Perceived stress scale score for pregnant women in their 1st
trimester
First trimester (n=46) Correlation with PSS† p-Value‡ Age (mean(SD)) 29.9 (4.8) n.s. − Gestational Week (mean (SD)) weeks 12.3 (1.8) n.s. − Parity (no.(%))
Primipara
Multipara 21 (45.7)25 (54.3)
− n.s. Previous child (no.(%))
1 2 3 or more 15 (32.6) 9 (19.6) 1 (2.2) n.s. − Employed (no.(%)) Yes No 20 (43.5)26 (56.5) − n.s. BMI (mean(SD) 20.8 (2.3) n.s. − Household (no.(%))
married with no children nuclear family extended family other 20 (43.5) 19 (41.3) 6 (13.0) 1 (2.2) − n.s.§
Perceived stress scale score 20.7 (5.9) − − † Pearson’s product-moment correlation was used to examine the relation between the Perceived stress scale score and
demographic variables
‡ Un-paired t-test was used to test for significant differences between Perceived stress scale and demographic variables § One-way ANOVA was used to test for significant differences between Perceived stress scale and household type n.s.=not significant, −=not analyzed
Table 2 Means and standard deviations of component and global scores of the Pittsburgh Sleep Quality Index (PSQI) for first trimester expectant mothers
(N=46) Score Mean S.D. Component score Sleep quality Sleep latency Sleep duration Sleep efficiency Sleep disturbance Hypnotic medication use Daytime dysfunction Global scale 1.22 1.22 0.87 0.70 1.22 0.00 1.15 6.67 0.76 1.02 0.83 0.87 0.66 0.00 0.76 3.20 0 2 4 6 8 10 12 14 16 0 1 3 4 5 6 8 9 10 11 13 14 15 16 18 19 20 21 23 24 Rate Time of Day
Figure 1 Rate of sleepiness of first trimester expectant mothers
Rate of sleepiness is calculated from sleep log data of 46 par-ticipants, with a total of 197 days.
Participants who had perceived sleepiness recorded sleepi-ness at 15 minute intervals. The number of participants who perceived sleepiness at each interval was divided by the total number of days (197) to give the sleepiness rate.
Periods of sleepiness occurred throughout the day, from imme-diately after rising until bedtime. Average rising times and bed-times were 7:18 (±1.58) and 22:94(±1.22), respectively. There are two peaks for perception of sleepiness, one at 11:00, and the second from 14:00 to 15:00. More than 10% of participants perceived sleepiness between 13:30 and 16:00.
of participants perceived sleepiness between 13:30 and 16:00. In addition to nocturnal sleep time, 29 participants reported daytime naps or time spent in bed averaging 70.4 minutes (7.5 min to 4 hr 25 min). There was no sig-nificant relationship between ESS scores and duration of sleepiness, or nap duration.
4. Factors Relating Sleep and Sleepiness
(1) There was no significant relationship between PSQI scores and parity, employment, or any other participant attribute. On the other hand, there was positive correla-tion between PSQIG and PSS scores (PSQIG: r = 0.38, n = 46, p<0.01). Sleep quality (r=0.39, n=46, p<0.01), sleep disturbance (r=0.42, n=46, p<0.01) and daytime dysfunction (r=0.33, n=46, p<0.05) were positively correlated with PSS scores. Moreover, the average SD for bedtime and rising time was 0.67(±0.52) hours and 0.60(±0.59) hours, respectively. PSQI was positively correlated with bedtime SD (r=0.40, n=46, p<0.01). In other words, participants who kept regular bedtimes had
lower PSQI scores (Table 4).
(2) ESS scores for primipara were significantly higher (un-paired t (44)=2.52, p<0.05) than scores for multipa-ra. Moreover, a negative correlation was found between the number of children (r=-0.32, n=46, p<0.05) and ESS scores. Duration of sleepiness was correlated with age (r=-0.32, n=39, p<0.05). For participants who were able to take naps, there was a significant difference (un-paired t(27)=2.27, p<0.05) in average nap time between employed (11 participants, 55.0%), 39.8 (±29.9) min-utes and not employed (18 participants, 69.2%), 89.1 (± 67.9) minutes. There was no relationship between ESS scores and, length of sleepiness, sleep habits SD, em-ployment, BMI, or PSS score (Table 4).
IV. Discussion
This research has clarified sleep quality and sleepi-ness characteristics of first trimester women using PSQI, ESS, and sleep logs. Moreover, we have also clarified
Characteristics sleepiness or
napping Mean Standard error Range Start time of sleepiness
(time of day) 37 14.00 2.80 8.25 21.50 End time of sleepiness
(time of day) 37 15.21 2.73 9.00 23.00 Sleepiness duration
(minutes) 37 72.4 33.6 25.0 180.0 Nap duration (including time spent in bed)
(minutes) 29 70.4 60.9 7.5 265.0 Note. Each is derived from the average of individual participants sleep log data
Table 4 Correlations between sleep quality, sleepiness characteristics, and related factors
Regularity of sleep habits† Age Number of children PSS Bedtime Rising time PSQIG Sleep quality Sleep latency Sleep duration Sleep efficiency Sleep disturbance Daytime dysfunction ESS Sleepiness duration n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. −0.32 * n.s. n.s. n.s. n.s. n.s. n.s. n.s. −0.32 n.s. * 0.38 0.39 n.s. n.s. n.s. 0.42 0.33 n.s. n.s. ** ** ** * 0.42 n.s. 0.30 n.s. 0.44 n.s. n.s. n.s. n.s. ** * ** n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. Note. Definition of abbreviations: PSQIG: Pittsburgh sleep quality index Global score; ESS: Epworth sleepiness scale
†Regularity of sleep habits were indicated by the mean of standard deviation of each time for participants. *p<.05, **p<.01
Sleep quality and sleepiness characteristics in first trimester expectant mothers
the relationship of stress to sleep quality and to sleepi-ness characteristics.
In this investigation, the average PSQI score was 6.67 points, and 65.2% of participants exceeded the cut-off. Thus, we confirmed that expectant mothers have lowered sleep quality during the first trimester. Accord-ing to an investigation of Japanese women in their 20s and 30s, the PSQIG scores and percentage exceeding the cut-off value were 5.30 (±2.48) and 36.4%, and 4.44 (±2.09) and 25.4%, respectively (Doi et al., 2001). Based on our investigation, we can say that sleep quality of first trimester expectant mothers is markedly lower than women in their 20s and 30s in the general popula-tion.
Numerous studies of sleepiness during pregnancy utilize original questionnaires, but little research has been done using standardized scales such as the ESS or the PSQI. This research has particular significance because we measured the level of perceived sleepiness during the first trimester utilizing standardized assess-ments. In our study the ESS average score of 10.2 (±4.3) points was higher than the average of 8.6 points found in a study of a sample of Chinese expectant mothers (Leung et al., 2005). Furthermore, a high percentage of participants in this study, more than 50%, were di-agnosed to have EDS. Takegami (2005) has found that women in their 20s and 30s in the general population have EDS rates of 11.5% and 5.7%, respectively. Okun et al. (2007) have reported no significant difference in daytime sleepiness in pregnant and non-pregnant women. However, our results suggest that a consider-able number of expectant mothers in their first trimester perceive sleepiness to an extent that it poses a potential hindrance to their daily life. Moreover, expectant moth-ers perceive sleepiness throughout the day, from wak-ing time to bedtime, and in particular, more frequently between 13:00 to 16:00. We find it interesting that there is no relationship between duration of sleepiness and strength of sleepiness, or between strength of sleepiness and nap duration.
This study investigates factors that influence first trimester sleep quality. Our results suggest that stress levels and the regulation of sleep habits influence sleep quality. In particular, expectant mothers who evaluate
their sleep quality as low, or who report frequent sleep disturbances, have strongly perceived stress. This sug-gests that there is a relationship between sleep and stress levels, as in the general adult population (Suka et al., 2003). These stress levels are not related to attributes such as age or employment. Moreover, stress is not cor-related with minor symptoms, such as nausea and back pain, or physiological changes associated with pregnan-cy such as gestational week. This suggests that first tri-mester sleep quality is related to, as Cohen et al. (1983) have said, the degree to which respondents feel stress in their daily-life situations. On the other hand, expectant mothers who retire to bed at consistent times most days have higher sleep quality. There was no difference in PSQI scores between employed or not-employed par-ticipants. However, a study of first trimester expectant mothers that included a similar percentage of multipara (Okun et al., 2007: 42.9%) as our study (54.3%), report-ed lower PSQI scores (4.76±2.3, n=35). In Okun et als.’ study 82.9% of expectant mothers were working, while in our investigation only 43.5% of expectant mothers were working. Therefore, we might speculate that be-cause an employed expectant mothers’ daily habits are more regulated than an unemployed expectant mother, Okun’s reported PSQI scores would be lower. Thus, this study suggests that a well-regulated life is essential to improving sleep quality.
Primipara perceive stronger daytime sleepiness than multipara, and the more children multipara have the lower is their perceived level of sleepiness. More-over, younger mothers feel sleepiness longer. ESS scores for women in general population in their 20s (5.65±3.92) are higher than scores for women in their 30s (4.64±3.34) (Takegami et al., 2005). Our results are similar to Takegami’s, as younger expectant mothers perceive stronger sleepiness. In addition, mothers who have stronger daytime dysfunction have stronger per-ceived stress. Expectant mothers who perceive higher levels of stress feel stronger daytime sleepiness, a result similar to that reported in a study of the general popula-tion (Kaneita et al., 2005). Until now, researchers have observed the relationship of daytime sleepiness to snor-ing and diseases such as SDB and PIH (Franklin et al., 2000; Leng et al., 2006). On the other hand, Izci et al.,
can say that further investigation into factors related to sleepiness is necessary.
There are many self-care interventions available to expectant mothers such as intentionally retiring early and establishing a specific time period for rest in bed. Having made clear first trimester sleep architecture, we hope this research has provided evidence that will be useful in improving methods of self-care for expectant mothers, and ultimately improve their quality of life.
In conclusion, this study has shown that, when compared to same age women in the general population, markedly more first trimester expectant mothers have poor sleep quality, 65.2% exceeded the cut-off score; and have markedly higher ESS scores, 50.0% were re-garded as having EDS. Expectant mothers who have high PSQI scores have significantly higher PSS scores which indicate the degree of perceived stress. More-over, expectant mothers who retire to bed at consistent times most days have lower PSQI scores. In addition, primipara perceive higher levels of daytime sleepiness than multipara, and the more children multipara have the lower is their perceived level of sleepiness. There was no significant difference in duration of sleepiness and parity, or nap time and parity. For the attribute of employed or not employed, there was a significant dif-ference for nap time, but no significant difdif-ference for sleepiness duration.
Acknowledgements
We would like to sincerely thank the doctors, nurs-ing directors, nursnurs-ing staff of Kouseiren Hiroshima Hospital and Masaoka Hospital, and participants for their cooperation in this research. We would also like to thank Roger L. Reinoos for his assistance in translating this article.
References
Akimoto, H., Honda, Y. & Takahashi, Y. (1960). Pharmaco-therapy in narcolepsy. Diseases of the Nervous System, 21, 704-706.
Cohen, S., Kamarack, T. & Mermelstein, R. (1983). A global measure of perceived stress. Journal of Health and
So-probability sample of the United States. In S. Spacapan, & S. Oskamp (Eds.), The social psychology of health (31-67). Newbury Park, CA: Sage.
Corwin E. J., Brownstead J. & Barton N. et al. (2005) The impact of fatigue on the development of postpartum de-pression. JOGNN, 34, 577-586.
Doi, Y. & Minowa, M. (2003). Gender differences in exces-sive daytime sleepiness among Japanese workers. So-cial Science Medicine, 56(4), 883-894.
Doi, Y., Minowa, M. & Uchiyama, M. et al. (2000). Psycho-metric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects. Psychiatry Research, 97, 165-172.
Doi, Y., Minowa, M. & Uchiyama, M. et al. (2001). Subjec-tive sleep quality and sleep problems in the general Japa-nese adult population. Psychiatry and Clinical Neurosci-ence, 55, 213-215.
Franklin, K.A., Holmgren, P.A. & Jonsson, F. et al. (2000). Snoring, pregnancy-induced hypertension, and growth retardation of the fetus. Chest, 117, 137-141.
Fukuhara S., Takegami M. & Suzugamo Y. et al. (2006). The Japanese version of the Epworth Sleepiness Scale (JESS): Main differences and revisions between the Japanese version of the Epworth Sleepiness Scale (JESS) and pre-vious versions, The Journal of the Japanese Respiratory Society, 44(11), 896-898. (in Japanese)
Hedman, C., Pohjasvaara, T. & Tolonen, U. et al. (2002). Ef-fects of pregnancy on mothers’ sleep. Sleep Medicine, 3, 37-42.
Hertz, G., Fast, A. & Feinsilver, S.H. et al. (1992). Sleep in normal late pregnancy. Sleep, 15(3), 246-251.
Hurley K.M, Caulfield L.E. & Sacco L.M. et al. (2005) Psy-chosocial influences in dietary patterns during pregnan-cy. Journal of the American Dietetic Association, 105, 963-966.
Izci, B., Martin, S.E. & Dundas, K.C. et al. (2005). Sleep complaints: snoring and daytime sleepiness in pregnant and pre-eclamptic women. Sleep Medicine, 6, 163-169.
Johns, M.W. (1991). A new method for measuring daytime sleepiness: the Epworth Sleepiness Scale. Sleep, 14(6),
Sleep quality and sleepiness characteristics in first trimester expectant mothers
540-545.
Johns, M.W. (1993). Daytime sleepiness, snoring, and ob-structive sleep apnea: The Epworth Sleepiness Scale. Chest, 103, 30-36.
Johns, M.W. (2000). Sensitivity and specificity of the mul-tiple sleep latency test (MSLT), the maintenance of wakefulness test and the Epworth Sleepiness Scale: Failure of the MSLT as a gold standard. Journal of Sleep Research, 9, 5-11.
Kaneita, Y., Ohida, T. & Uchiyama, M. et al. (2005). Exces-sive Daytime Sleepiness among the Japanese general population. Journal of Epidemiology, 15(1), 1-8. Kim K., Uchiyama M. & Okawa M. et al. (2000). An
epide-miological study of insomnia among the Japanese gen-eral population. Sleep, 32(1), 41-47.
Lancel, M., Faulhaber, J. & Holsboer, F. et al. (1996). Proges-terone induces changes in sleep comparable to those of agonistic GABAA(check this last letter) receptor modula-tors. American Physiological Society, 271, E763-E772. Lee, K.A., Zaffke, M.E. & McEnany, G. (2000). Parity and
sleep patterns during and after pregnancy. Obstetrics & Gynecology, 95(1), 14-18.
Leng, P.H., Mosharraf-Hossain, A.K. & Chan, Y.H. et al. (2006). The clinical predictors of hypertension and sleepiness in an Asian population with sleep-disordered breathing. Annals Academy of Medicine, 35(1), 6-10. Leung, P.L., Hui, D.S. & Leung, T.N. et al. (2005). Sleep
dis-turbances in Chinese pregnant women. International Jour-nal of Obstetrics and Gynecology, 112(11), 1568-1571. Loube, D.I., Poceta, J.S. & Morales, M.C. et al. (1996).
Self-reported snoring in pregnancy: Association with fetal outcome. Chest, 109, 885-889.
Nakata, A., Haratani, T. & Takahashi, M. et al. (2004). Job stress, social support, and prevalence of insomnia in a population of Japanese daytime workers. Social Sci-ence & Medicine 59(8), 1719-1730.
Okun, M.L. & Coussons-Read M.E. (2007) Sleep disruption during pregnancy: How does it influence serum cyto-kines? Journal of Reproductive Immunology, 73, 158-165.
Shimada M., Segawa M. & Higurashi M. et al (1993) Devel-opment of the sleep and wakefulness rhythm in preterm infants discharged from a neonatal care unit. Pediatric Research, 33(2), 159-163.
Suka, M., Yoshida, K. & Sugimori, H. (2003). Persistent in-somnia is a predictor of hypertension in Japanese male workers. Journal of Occupational Health, 45, 344-350. Sumi, K. (1997). Optimism, social support, stress, and
phys-ical and psychologphys-ical well-being in Japanese women. Psychological Reports 81(1), 299-306.
Suzuki, S., Dennerstein, L. & Greenwood, K.M. et al. (1994). Sleeping patterns during pregnancy in Japanese women. Journal of Psychosomatic Obstetrics and Gynecology, 15, 19-26.
Takegami, M., Sokejima, S. & Yamazaki, S. et al. (2005). An estimation of the prevalence of excessive daytime sleepi-ness based on age and sex distribution of Epworth Sleep-iness Scale scores: A population based survey. Japanese Journal of Public Health, 52(2), 137-145. (in Japanese)
新 川 治 子＊1，島 田 三恵子＊2，藤 田 照 美＊3 ＊1大阪大学大学院医学系研究科保健学専攻博士後期課程 ＊2大阪大学大学院医学系研究科 ＊3JA広島厚生連 廣島総合病院 抄 録 目 的 睡眠は正常な妊娠経過や胎児の発育にとって重要である。そのため，妊娠初期の妊婦に適切なセルフ ケアのための知識や助言を提供することが必要である。そこで，本研究は妊娠初期の睡眠や眠気のパ ターンを明らかにすることを目的とする。また，それらとストレスなどの要因との関係を明らかにする ことを目的とする。 方 法 広島県内の2病院の産婦人科外来で妊婦健康診査を受けている妊婦46名から自記式質問紙を回収した。 調査期間は2007年4月から2008年1月までである。質問紙は，ピッツバーグ睡眠調査票（PSQI），エップ ワース眠気尺度（ESS），睡眠日誌，及び知覚されたストレス尺度より構成した。 結 果
PSQI合計得点（PSQIG）は平均6.67（ 3.20）であり，65.2％の妊婦がCut off値以上であった。PSQIGは ストレスの高い妊婦で有意に高かった（r＝0.38, n＝46, p＜0.01）。PSQIGと就床時刻の規則性には有意 な正の相関があり（r＝0.40, n＝46, p＜0.01），規則正しく就床している者ではPSQIG得点が低くなって いた。平均ESS得点は10.1（ 4.3）で，50％の妊婦が11点以上であった。また，ESS得点は経産婦よりも 初産婦で高かく（un-paired t (44)＝2.52, p＜0.05），子どもの人数が多いほど得点が低かった（r＝0.32, n＝46, p＜0.05）。眠気時間や昼寝の長さは初経産別で差がなかった。仕事の有無により昼寝時間に差 は見られたが（un-paired t (27)＝2.27, p＜0.05），眠気時間との間には差がなかった。 結 論 本研究により，妊娠初期には同世代の一般女性と比べて，睡眠の質が悪い人や日中に過度の眠気を感 じている人が著しく多いことが明らかとなった。また，睡眠の質はストレスのコントロールや，規則正 しい就床により高めることができることが示唆された。 キーワード：睡眠の質，眠気，妊娠初期，ストレス
