Maternal sleep practices and stillbirth: Findings from an international case‐control study

Abstract

Background: Late stillbirth, which occurs ≥28 weeks' gestation, affects 1.3-8.8 per 1000 births in high-income countries. Of concern, most occur in women without established risk factors. Identification of potentially modifiable risk factors that relate to maternal behaviors remains a priority in stillbirth prevention research. This study aimed to investigate, in an international cohort, whether maternal sleep practices are related to late stillbirth. Methods: An Internet-based case-control study of women who had a stillbirth ≥28 weeks' gestation within 30 days before completing the survey (n = 153) and women with an ongoing third-trimester pregnancy or who had delivered a live born child within 30 days (n = 480). Bivariate and multivariate logistic regressions were used to determine unadjusted and adjusted odds ratios (OR and aOR, respectively) with 95% confidence intervals (95% CIs) for stillbirth. Results: Sleeping >9 hours per night in the previous month was associated with stillbirth (aOR 1.75 [95% CI 1.10-2.79]), as was waking on the right side (2.27 [1.31-3.92]). Nonrestless sleep in the last month was also found to be associated with stillbirth (1.73 [1.03-2.99]), with good sleep quality in the last month approaching significance (1.64 [0.98-2.75]). On the last night of pregnancy, not waking more than one time was associated with stillbirth (2.03 [1.24-3.34]). No relationship was found with going to sleep position during pregnancy, although very few women reported settling in the supine position (2.4%). Conclusions: Long periods of undisturbed sleep are associated with late stillbirth. Physiological studies of how the neuroendocrine and autonomic system pathways are regulated during sleep in the context of late pregnancy are warranted. K E Y W O R D S maternal sleep, sleep duration, stillbirth | 345 O'BRIEN Et al.

Associations between symptoms of sleep-disordered breathing and maternal sleep patterns with late stillbirth: Findings from an individual participant data meta-analysis

“…25 Prespecified potential covariates were: maternal age, earliest pregnancy BMI, ethnicity, parity, education level, marital status, pre-existing hypertension or diabetes, smoking, recreational drug use, supine going-to-sleep position, fetal movements, infant birthweight by customised centiles, and measures of SDB and sleep patterns ('any' snoring, habitual snoring, the Berlin Questionnaire [BQ], Epworth Sleepiness Scale [ESS], sleep quality, sleep restlessness, and sleep duration). Frequency of getting up to use the toilet and daytime naps were also included as these are previously reported [26,[30][31][32] independent risk factors for late stillbirth. Where data exists for multiple time frames, only data for the month prior to the stillbirth were used in the analysis.…”

“…This IPD meta-analysis was registered with the PROSPERO register of systematic reviews (CRD42017047703) and followed the IPD meta-analysis protocol [38], search strategy [24], risk of bias for non-randomised studies (ROBINS-E) tool [39], and published results [24]. Five international case-control studies [26,27,[30][31][32] that collected maternal going-to-sleep position and late stillbirth data were included in this pooled IPD meta-analysis.…”

“…Exclusion criteria were multiple pregnancy, major congenital abnormality, gestation <28 weeks' when pregnancy sleep data was collected, termination of pregnancy at �28 weeks', and receiving an intervention that may have affected going-to-sleep position. Maternal sleep data were collected by self-report via face-to-face interview [26,27,30,31] or online survey [32] within six weeks after stillbirth in cases or at a matched gestation in controls.…”

“…A meta-analysis [25], which included the comparison of stillbirth in women with and without SDB as an outcome measure, using subjective (self-reported snoring) [26,27] and objective (OSA) [9,28,29] measurements, reported no association between SDB and stillbirth. The relationship between sleep duration and late stillbirth was reported in several case-control [26,[30][31][32] and cross sectional studies [33], however, the results are not consistent in identifying an association. Subjective sleep quality was also not associated with stillbirth in a cross-sectional [33] and case-control [32] study.…”

“…The relationship between sleep duration and late stillbirth was reported in several case-control [26,[30][31][32] and cross sectional studies [33], however, the results are not consistent in identifying an association. Subjective sleep quality was also not associated with stillbirth in a cross-sectional [33] and case-control [32] study. Other case-control studies [26,30] reported that daily naps, compared to no naps, were independently associated with late stillbirth.…”