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. 2022 Apr 11;45(4):zsac032.
doi: 10.1093/sleep/zsac032.

Polysomnographic analysis of maternal sleep position and its relationship to pregnancy complications and sleep-disordered breathing

Danielle L Wilson  1   2 , Alison M Fung  3 , Gabrielle Pell  2 , Hannah Skrzypek  3 , Maree Barnes  1   4 , Ghada Bourjeily  5 , Susan P Walker  2   3 , Mark E Howard  1   4
Affiliations

Polysomnographic analysis of maternal sleep position and its relationship to pregnancy complications and sleep-disordered breathing

Danielle L Wilson et al. Sleep. .

Abstract

Links between supine "going to sleep" position and stillbirth risk have led to campaigns regarding safe maternal sleep position. This study profiles the distribution of sleep positions overnight and relationships to sleep onset position during pregnancy, and the relationships between supine sleep, sleep-disordered breathing (SDB), and pregnancy outcomes. Data from three prospective cohort studies evaluating SDB in healthy and complicated pregnancies were pooled. All participants underwent one night of polysomnography in late pregnancy and birth outcome data were collected. 187 women underwent polysomnography at a median gestation of 34 weeks'. The left lateral position was preferred for falling asleep (52%) compared to supine (14%), but sleep onset position was the dominant sleep position overnight in only half (54%) of women. The median percentage of sleep time in the supine position was 24.2%; women who fell asleep supine spent more time supine overnight compared to those who began non-supine (48.0% (30.0,65.9) vs. 22.6% (5.7,32.2), p < .001). Women with growth-restricted fetuses were more likely to fall asleep supine than those with well-grown fetuses (36.6% vs. 7.5%, p < .001). Positional SDB was observed in 46% of those with an RDI ≥ 5. Sleep onset position was the dominant position overnight for half of the sample, suggesting that sleep onset position is not always a reliable indicator of body position overnight. Supine sleep was related to fetal growth restriction and birthweight at delivery, though causality cannot be inferred. It is critical that we pursue research into verifying the important relationship between supine sleep and increased stillbirth risk, and the mechanisms behind it.

Keywords: birthweight; fetal health; lateral; polysomnography; pregnant; sleep apnea; sleep onset; sleep study; supine.

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Figures

Figure 1.
Figure 1.
Number of participants with uncomplicated or complicated pregnancies.
Figure 2.
Figure 2.
Distribution of percentage of total sleep time spent in the supine position for participants with supine sleep onset (n = 26) and participants with non-supine sleep onset (n = 161). Supine sleep onset was associated with more total sleep time in the supine position (48.0% (30.0, 65.9) compared to those who fell asleep in a non-supine position (22.6% (5.7, 32.2), p < .001).
Figure 3.
Figure 3.
A comparison of pregnant women with fetal growth restriction (FGR; n = 41) and appropriate for gestational age (AGA) fetuses (n = 146) on A) sleep onset position, χ 2 (3) = 23.70, p < .001; and B) median (IQR) percentage of total sleep time in each position compared with separate Mann–Whitney U tests. The higher percentage of time spent overnight in the supine position in the FGR group was no longer significant after adjusting for gestational age at the time of the sleep study (p = .059).
Figure 4.
Figure 4.
Respiratory disturbance index (RDI per hour) overall (n = 174) and in REM (n = 116) and NREM (n = 174) sleep for supine and non-supine body position. Note: extreme outliers have been removed.
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References

    1. Cronin RS, et al. An individual participant data meta-analysis of maternal going-to-sleep position, interactions with fetal vulnerability, and the risk of late stillbirth. EClinicalMedicine. 2019;10:49–57. - PMC - PubMed
    1. Owusu JT, et al. Association of maternal sleep practices with pre-eclampsia, low birth weight, and stillbirth among Ghanaian women. Int J Gynaecol Obstet. 2013;121:261–265. - PMC - PubMed
    1. Anderson NH, et al. Association of supine going-to-sleep position in late pregnancy with reduced birth weight: a secondary analysis of an individual participant data meta-analysis. JAMA Netw Open. 2019;2(10):e1912614. - PMC - PubMed
    1. Humphries A, et al. The effect of supine positioning on maternal hemodynamics during late pregnancy. J Matern Fetal Neonatal Med. 2019;32(23):3923–3930. - PubMed
    1. Cure Kids. Sleep on side when baby’s inside from 28 weeks of pregnancy.2018; cited 30 Dec 2021. Available from: https://www.sleeponside.org.nz/

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