Epidemiological study of the sleep problems among Japanese pregnant women

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 16614011
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 睡眠学
• Research Institution: Nihon University
• Principal Investigator: OHIDA Takashi Nihon University, School of Medicine, Dep.of Public Health, Professor, 医学部, 教授 (40321864)
• Co-Investigator(Kenkyū-buntansha): KANEITA Yoshitaka Nihon University, School of Medicine, Dep.of Public Health, Lecturer, 医学部, 専任講師 (40366571)
• Project Period (FY): 2004 – 2006
• Keywords: pregnant women / sleep / RLS / epidemiology / sleep problem

Research Abstract

To reexamine the prevalence of restless legs syndrome (RLS) among pregnant women in Japan based on the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG), and to epidemiologically clarify factors associated with RLS including sleep disorders and pregnancy status. 19,441 women with a confirmed pregnancy who had attended one of 344 clinical obstetric institutions for a second or subsequent consultation were subjected to analysis. Each subject was instructed to complete a self-administered questionnaire during the time spent waiting for a consultation. Univariate and multiple logistic regression analyses were conducted. The prevalence of RLS among the pregnant women was 2.9%. The prevalence by age group exhibited a U-shaped curve with the value for those in the thirties as a minimum. The prevalence became more than twice higher in the third trimester of pregnancy. There were stronger associations between RLS and third trimester of pregnancy, multipara, smoking, subjective insufficient sleep, difficulty initiating sleep, early morning awakening, and excessive daytime sleepiness (OR:1.92,0.76,1.54,1.68,2.44,1.80,1.89,respectively). The prevalence of RLS among pregnant women in Japan was not as high as previously reported; similar to that for the general Japanese population. As the prevalence of RLS is lower than that in Western countries, genetic backgrounds may largely contribute to the observed differences. In this study, like others, the prevalence of RLS increased during the third trimester of pregnancy, and strong associations were observed between RLS and difficulty initiating sleep, and between RLS and difficulty maintaining sleep.