{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T03:27:32Z","timestamp":1777433252656,"version":"3.51.4"},"reference-count":52,"publisher":"BMJ","issue":"8","funder":[{"DOI":"10.13039\/501100004828","name":"Grand Challenges Canada","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100004828","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100009415","name":"IWK Health Centre","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100009415","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2018,6,22]]},"published-print":{"date-parts":[[2018,8]]},"abstract":"<jats:sec><jats:title>Objective<\/jats:title><jats:p>To evaluate whether the percentage of time spent supine during sleep in the third trimester of pregnancy could be reduced using a positional therapy device (PrenaBelt) compared with a sham device.<\/jats:p><\/jats:sec><jats:sec><jats:title>Design<\/jats:title><jats:p>A double-blind, randomised, sham-controlled, cross-over pilot trial.<\/jats:p><\/jats:sec><jats:sec><jats:title>Setting<\/jats:title><jats:p>Conducted between March 2016 and January 2017, at a single, tertiary-level centre in Canada.<\/jats:p><\/jats:sec><jats:sec><jats:title>Participants<\/jats:title><jats:p>23 participants entered the study. 20 participants completed the study. Participants were low-risk, singleton, third-trimester pregnant women aged 18 years and older with body mass index &lt;35 kg\/m<jats:sup>2<\/jats:sup>at the first antenatal appointment for the index pregnancy and without known fetal abnormalities, pregnancy complications or medical conditions complicating sleep.<\/jats:p><\/jats:sec><jats:sec><jats:title>Interventions<\/jats:title><jats:p>A two-night, polysomnography study in a sleep laboratory. Participants were randomised by computer-generated, one-to-one, simple randomisation to receive either a PrenaBelt or a sham-PrenaBelt on the first night and were crossed over to the alternate device on the second night. Allocation concealment was by unmarked, security-tinted, sealed envelopes. Participants, the recruiter and personnel involved in setting up, conducting, scoring and interpreting the polysomnogram were blinded to allocation.<\/jats:p><\/jats:sec><jats:sec><jats:title>Primary and secondary outcome measures<\/jats:title><jats:p>The primary outcome was the percentage of time spent supine during sleep. Secondary outcomes included maternal sleep architecture, respiration, self-reported sleep position and feedback.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The median percentage of sleep time supine was reduced from 16.4% on the sham night to 3.5% on the PrenaBelt night (pseudomedian=5.8, p=0.03). We were unable to demonstrate differences in sleep architecture or respiration. Participants underestimated the time they spent sleeping supine by 7.0%, and six (30%) participants indicated they would make changes to the PrenaBelt. There were no harms in this study.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>This study demonstrates that the percentage of sleep time supine during late pregnancy can be significantly reduced via positional therapy.<\/jats:p><\/jats:sec><jats:sec><jats:title>Trial registration number<\/jats:title><jats:p><jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"NCT02377817\" ext-link-type=\"clintrialgov\" specific-use=\"clinicaltrial results\">NCT02377817<\/jats:ext-link>; Results.<\/jats:p><\/jats:sec>","DOI":"10.1136\/bmjopen-2017-020256","type":"journal-article","created":{"date-parts":[[2018,8,29]],"date-time":"2018-08-29T15:49:14Z","timestamp":1535557754000},"page":"e020256","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":24,"title":["Modifying maternal sleep position in the third trimester of pregnancy with positional therapy: a randomised pilot 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