Output list
1–10 of 31 results
Journal article
First online publication 21-Jul-2026
CHEST, Advanced access
Background
OSA is associated with significant morbidity in pregnancy. Minimal guidance is available on how best to screen, diagnose, treat, and re-evaluate for OSA in pregnant patients. Considering the potentially adverse consequences of OSA in pregnancy if left untreated, we assembled a panel of experts to review the available literature methodologically and make evidence-based recommendations.
Methods
Rigorous methodology was applied to provide a trustworthy evidence-based guideline and expert panel report. Panelists developed key clinical questions using the population, intervention, comparator, and outcome (PICO) format, addressing specific topics in OSA in pregnant individuals. MEDLINE (via PubMed) and the Cochrane Library were searched systematically for relevant literature and were supplemented by manual searches. References were screened with study evaluation tools to assess for inclusion, to extract meaningful data, and to grade the level of evidence to support each recommendation or suggestion.
Results
PICO questions related to screening, diagnosis, treatment, and follow-up of OSA in pregnant patients resulted in 9 conditional recommendations made with the evidence available and with the consensus of the expert panel. We recommend screening pregnant patients for OSA, either with a pregnancy-specific screening questionnaire or a standard tool. For those at risk of OSA based on screening, either a home sleep test or in-laboratory polysomnography is recommended for diagnosis. We recommend treatment for those with an apnea-hypopnea index (AHI) of 5 to 15 who have symptoms and sequelae or comorbidities, or those with an AHI of ≥ 15 regardless of symptoms or comorbidities, preferably with autotitrating positive airway pressure. Additionally, scheduled naps may be beneficial as an initial step in alleviating residual symptoms. Reassessment of OSA in the postpartum period is recommended in some patients.
Interpretation
Because of the low level of certainty, 9 conditional recommendations were made for the screening, testing, and treatment of OSA in pregnancy.
Journal article
Objectively Measured Maternal Supine Sleep and Fetal Growth: A Prospective Cohort Study
First online publication 13-Apr-2026
BJOG, Advanced access
Objective
To explore the relationship between different definitions of objectively measured supine sleep position during late pregnancy and customised birthweight centile, as a marker of fetal wellbeing.
Design
Prospective cohort study.
Setting
Australian public hospital antenatal clinic.
Population
Eighty-four pregnant women from 32–36 weeks of gestation.
Methods
Body position was measured in degrees of roll using a tri-axial accelerometer worn around the abdomen for seven sequential nights. Supine was defined as ‘broad supine’ (0° = fully supine to 45° left/right tilt), and ‘supine low-tilt’ (0°–15°). Two additional Risk Indices capturing risk proportional to duration spent in each degree of supine-to-lateral tilt were developed. Birthweights were converted into customised centiles using GROW software.
Main Outcome Measures
The primary outcome was customised birthweight centile. Secondary outcomes included birthweight, gestational age at delivery, and fetal growth trajectory.
Results
Across 556 nights of data, the median nightly duration of broad supine positioning was 65.9 [25.0, 125.7] minutes compared to only 9.1 [0.7, 24.4] minutes of supine low-tilt. There was no relationship between customised birthweight centile and time spent in broad supine (R2 = 0.0027, F(1,82) = 0.22, p = 0.64) or supine low-tilt (R2 = 0.0029, F(1,82) = 0.24, p = 0.63); nor with any supine risk index and customised birthweight centile, birthweight, gestational age at delivery, or fetal growth trajectory.
Conclusion
In this cohort, there was no evidence of an association between objectively measured supine sleep and customised birthweight centile. Yet to be identified mechanisms unrelated to fetal growth may be responsible for supine going-to-sleep position being a risk factor for late stillbirth. Further prospective investigation is needed to untangle cause and effect; however, given the low rate of stillbirth, such a study may not be feasible.
Journal article
A Systematic Review of Obstructive Sleep Apnea in Indigenous Peoples Worldwide
Published 2026
Sleep Advances, 7, 3, 1 - 21
Study Objectives
Emerging evidence indicates that Indigenous peoples experience disproportionately high rates of obstructive sleep apnea (OSA). This systematic review aimed to examine OSA prevalence, contributing factors, and intervention or treatment outcomes among Indigenous peoples worldwide.
Methods
We systematically searched PubMed, Embase, CINAHL, Cochrane CENTRAL, ATSI Health, Web of Science and PsycINFO (last searched 30 June, 2025), and grey literature for original research involving Indigenous peoples (≥18 years) diagnosed with OSA via self-report or laboratory-based measures (e.g., polysomnography). Data extraction focused on study characteristics and key findings. Methodological quality was assessed using NIH tools, and cultural appropriateness was evaluated using the CREATE Aboriginal and Torres Strait Islander Quality Appraisal Tool. A narrative synthesis was conducted.
Results
From 599 records, 41 studies from six countries were included. OSA prevalence among Indigenous populations varied widely (community-based samples, 6.5%-69%; referred samples, 85-95%; self-reported diagnosis, 1.2%-8.4%; hospital audit diagnoses, 0.8-11.4%), with only one study reporting a robust population-based estimate (~6.5% among Māori). Severe cases predominated in referred samples. Factors associated with OSA included male sex, age, BMI, neck circumference, craniofacial and geographic factors, and symptoms such as snoring. Treatment evidence was limited to CPAP, with low adherence.
Conclusions
Findings suggests that OSA is common among Indigenous peoples across diverse settings. However, prevalence estimates are heterogeneous and limited by differences in study design, sampling frame, and diagnostic approaches, with most evidence based on referred clinical samples. Improving awareness and culturally responsive screening and management may improve outcomes. Sleep health among Indigenous peoples warrants a higher priority in research, policy and practice.
Registration
The protocol for this systematic review was registered with Prospero (CRD42024466932).
Journal article
Published 2026
Sleep and Breathing, 30, 1, 1 - 11
Purpose
Accuracy of patient-perceived sleeping position has implications for the acquisition and interpretation of sleep studies, implementation of positive airway pressure (PAP) therapies, and determining efficacy of positional therapies at home. This study aimed to compare self-reported supine sleep to observed supine sleep on polysomnography (PSG) and identify patient-related factors that contribute to supine sleep misperception.
Methods
A retrospective review of clinical PSG records from a public sleep service was performed. Body position was measured with a Grael position sensor with manual editing based on digital video if discrepant. Each patient completed a sleep questionnaire including questions regarding sleep position on the PSG. Self-reported supine sleep was divided into categories of “None/Some/Half/Most/All”, with PSG-measured supine sleep as a percentage of total sleep time (%TST) classified into these categories based on the cut-points of 0, 2.5, 33.3, 66.6, 97.5 and 100%. Absence of supine sleep on PSG was defined by the cut-point of “None” (≤ 2.5%TST). Chance-adjusted agreement between objective and subjective measures was assessed using the Cohen’s kappa statistic (linear weighting).
Results
A total of 956 patient records were available for analysis. 93% of patients who self-reported supine sleep on the PSG were correct, whereas only 56% of those who denied supine sleep accurately reported the absence of supine sleep on PSG. Patients who reported not sleeping on their back during the PSG had 11.0 ((95% CI: 7.0, 17.3), p < .001) times the odds of sleep position misperception than those who did report sleeping on their back. Agreement with self-reported categories of “None/Some/Half/Most/All was only moderate (kappa 0.45 [95% CI 0.43, 0.48]). Younger patients (< 55 years) and females were more likely to under-report supine sleep.
Conclusions
Patients denying supine sleep in the laboratory were more likely to misperceive sleep position on PSG, with younger females under-reporting supine sleep. Understanding contributors to misperception may influence decisions regarding supine sleep sampling in the laboratory, as well clinical decision making.
Journal article
"Sleep on side": Awareness and anxiety around sleeping position during late pregnancy
Published 2025
Women and Birth, 38, 6, 1 - 6
Background
The “Sleep on Side” policy was recently introduced in Australian antenatal clinics to reduce the risk of late stillbirth associated with going-to-sleep on the back.
Aim
To assess knowledge of side sleeping recommendations in pregnancy and explore feelings of anxiety in relation to this policy, and how these feelings may impact sleep.
Methods
Cross-sectional study of sleep position measured for seven nights between 32 and 36 weeks of pregnancy. Participants completed a sleep diary each morning, and at the end of the week completed a survey regarding knowledge and anxiety around sleeping position.
Findings
Sleep position data was collected in 80 participants, with 43 participants completing anxiety surveys. Almost all participants (95 %) reported receiving side sleeping advice during pregnancy, the most common source being their antenatal care provider. Twenty-three percent of women reported “moderate” or “very much” anxiety around their sleeping position or waking on their back overnight. Anxiety towards sleeping position was associated with self-reported supine sleep (p < .001), and use of additional pillows to support behind the back (p < .001). Overall self-reported sleep quality was not affected by anxiety, apart from alertness upon awakening (p = .001).
Discussion
In this cohort, the Sleep on Side policy has been disseminated widely with women understanding the rationale for encouraging a safe sleeping position. While many women receive this advice with minimal worry, almost a quarter of women may experience anxiety that may potentially affect their sleeping behaviour.
Conclusion
Advice on sleeping position should be carefully balanced with potential harms to maternal sleep and mental health.
Journal article
Published 2025
BJOG, 132, 2, 145 - 154
Objective
To assess the effectiveness and acceptability of a pillow-like position modification device to reduce supine sleep during late pregnancy, and to determine the impacts on the severity of sleep-disordered breathing (SDB) and foetal well-being.
Design
Randomised cross-over study.
Setting and Population
Individuals in the third trimester of pregnancy receiving antenatal care at a tertiary maternity hospital in Australia.
Methods
Participants used their own pillow for a control week and an intervention pillow for a week overnight, in randomised order. Sleep position and total sleep time for each night of both weeks were objectively monitored, with a sleep study and foetal heart rate monitoring performed on the last night of each week.
Main Outcome Measures
Primary outcome = percentage of sleep time in the supine position; secondary outcomes = apnoea–hypopnoea index, foetal heart rate decelerations and birthweight centile.
Results
Forty-one individuals were randomised with data collected on 35 participants over 469 nights. There was no difference in percentage of total sleep time in the supine position overnight between the control or intervention pillow week (13.0% [6.1, 25.5] vs. 16.0% [5.6, 27.2], p = 0.81 with a mean difference of 2.5% [95% CI] = −0.7, 5.6, p = 0.12), and no difference in the severity of SDB or foetal heart rate decelerations across weeks. However, increased supine sleep was significantly related to a higher apnoea–hypopnoea index (rs = 0.37, p = 0.003), lower birthweight (rs = −0.45, p = 0.007) and lower birthweight centile (rs = −0.45, p = 0.006). The proportion of supine sleep each night of the week varied widely both within and across participants, despite awareness of side-sleeping recommendations.
Conclusions
We found no evidence to suggest that the adoption of a pillow designed to discourage supine sleep was effective in late pregnancy, with women spending an average of 1 h per night supine. Alternative devices should be investigated, incorporating lessons learnt from this study to inform trials of supine sleep minimisation in pregnancy.
Trial Registration
Clinical Trial: (Australia New Zealand Clinical Trials Registry): ACTRN12620000371998
Journal article
The impact of study type and sleep measurement on oxygen desaturation index calculation
Published 2024
Journal of Clinical Sleep Medicine, 20, 5, 709 - 717
Study Objectives
The oxygen desaturation index (ODI) is an important measure of sleep-disordered breathing during polysomnography (PSG); however, the AASM Manual (V3) does not specify whether to include oxygen desaturations occurring during wake epochs. Additionally, an ODI obtained from PSG can differ from an ODI using home sleep apnea tests (HSATs) that do not measure sleep, hampering diagnostic and treatment decision reliability. This study aimed to (1) compare an ODI that included all desaturations with an ODI that excluded desaturations occurring during wake epochs in PSG and (2) compare ODIs obtained from PSG with HSAT.
Methods
100 consecutive PSGs for investigation of obstructive sleep apnea were compared. ODIs were calculated including all desaturations (ODIall) and by excluding desaturations entirely during wake epochs (ODIsleep). Additionally, we compared ODIall with an ODI calculated using monitoring time as the denominator (ODIHSAT).
Results
The median (interquartile range) 3% ODI for ODIall was 22.8 (13.1, 44.1) events/h and ODIsleep was 17.6 (11.5, 35.2) events/h (median difference: –3.9 events/h [–8.2, –0.9]; 21.0% [8.7%, 33.2%]). This discrepancy was larger with increasing ODI and decreasing sleep efficiency. The ODIHSAT was 17.4 (11.3, 35.2) events/h and the median reduction in ODIHSAT vs ODIall was –4.5 (–10.9, –2.0) events/h (21.6%; 11.1%, 33.8).
Conclusions
ODI was significantly reduced when desaturations in wake epochs were excluded, and when ODI was based on monitoring time rather than sleep time, with the potential for underestimation of disease severity. Results suggest that ODI can differ substantially depending on the calculation and study type used, and that there is a need for standardization to ensure consistent diagnosis and treatment outcomes.
Journal article
Published 2024
Breastfeeding Medicine, 19, 1, 33 - 39
Background and Objective:
Melatonin in breast milk exhibits a 24-hour circadian rhythm, present in nighttime breast milk but nearly undetectable in daytime breast milk. Shift work can disrupt the circadian timing of individuals, evident in changes in melatonin in saliva and urine samples. However, it is unknown whether these changes are also reflected in breast milk from a shift working mother. The aim of this study was to investigate whether maternal circadian rhythm disturbance from shift work impacts the melatonin concentration in breast milk.
Materials and Methods:
Breast milk and saliva samples were collected from 11 shift working mothers at four timepoints across five consecutive days. This included during their day shift or nonworkdays to act as a control, night shift, subsequent night shifts and postnight shift. Where possible, pre- and postfeed collections were also undertaken. Samples were grouped into four-time intervals: 12–6:30 am, 7–11:30 am, 12–6:30 pm, 7–11:30 pm, and melatonin levels (picogram per milliliter) in the breast milk and saliva samples were analyzed.
Results:
There was a significant decrease in breast milk melatonin (p = 0.026) at the 12–6:30 am time interval on subsequent night shifts, compared with control days. However, there was no overall time and shift type interaction effect (p = 0.70). In addition, no observed difference in melatonin levels was found in saliva samples, or when comparing pre- and postfeed breast milk. Breast milk melatonin however was found to be significantly higher compared with saliva (p > 0.001), at all but one time interval.
Conclusion:
The findings suggest that there is a potential effect of maternal circadian rhythm disruption from shift work on breast milk melatonin levels. This is an important step in exploring the role of maternal circadian timing and the effect on breast milk composition. Expansion of this research and exploration of other circadian rhythm misalignment sleep disorders on breast milk is highly recommended.
Journal article
Published 2024
BMC Pregnancy and Childbirth, 24, 1 - 8
Background
Sleep Disordered Breathing (SDB) in pregnant patients ranges from 3 to 27% and varies depending on gestational age and method used to diagnose. SDB increases the risk of advanced pregnancy complications such as gestational diabetes mellitus, pregnancy-induced hypertension, and preeclampsia. Screening and diagnosis of SDB during pregnancy remains a challenge, with existing screening tools underperforming during pregnancy. This study aimed to validate a previously developed model for predicting SDB during late pregnancy and compare the predictive value of bedpartner responses.
Methods
Ninety-six women in the third trimester of pregnancy underwent polysomnography and completed the Berlin Questionnaire (BQ), with 81 bedpartners completing the BQ about their pregnant partner. A subset of BQ items (snoring volume and tiredness upon awakening) along with BMI > 32 kg/m2was utilised to calculate the Wilson Optimized Model (WOM), which demonstrated strong predictive properties in development.
Results
SDB (RDI/hr ≥ 5) was detected in 43.8% of women. BQ identified 72% of pregnant mothers as high risk for SDB (Sensitivity = 83%, Specificity = 37%), compared to 29% of mothers identified by the WOM (Sensitivity = 45%, Specificity = 83%). At RDI of ≥ 15, the WOM correctly classified more women according to SDB risk than the BQ (76.0% vs. 41.7% cases correct,X2(1) = 23.42,p < .001), with no difference at RDI ≥ 5. Bedpartners were more likely to report high risk for SDB on the WOM than pregnant women themselves (38.3% vs. 28.4%), however predictive ability was not improved by bedpartner input (RDI ≥ 5 bedpartner AUC = 0.69 v mother AUC = 0.73).
Conclusion
BQ largely overestimates the prevalence of SDB in pregnancy compared to the WOM which underestimates. Utilising bedpartner responses didn’t improve screening for SDB in late pregnancy. More work is needed to develop a pregnancy-specific tool for quick and accurate screening for SDB.
Journal article
Published 2024
Sleep, 47, 2, 1 - 9
Study Objectives
Subjective recall of supine sleep during pregnancy has been linked to increased risk of stillbirth, but longitudinal, objective data are lacking. We aimed to examine how sleep position and breathing parameters change throughout pregnancy, and investigated associations between maternal supine sleep, assessed objectively in early and late gestation, and fetal growth velocity in high-risk women.
Methods
Women with singleton pregnancies and body mass index (BMI) ≥27 kg/m2 underwent level-III sleep apnea testing. Sleep position was assessed by accelerometry. We derived percentiles of estimated fetal weight and birthweight using FetalGPSR software, then calculated growth velocity as change in percentile/week between the second-trimester anatomy scan and birth.
Results
In total, 446 women were included, with N = 126 in the longitudinal sleep pattern analysis and N = 83 in the fetal growth analysis. Sleep-onset position and predominant sleep position were significantly correlated in both early (p = 0.001) and late (p < 0.01) pregnancy. However, supine going-to-bed position predicted predominant supine sleep in only 47% of women. Between early and late pregnancy there was a reduction in predominant supine sleepers (51.6% to 30.2%). Percent of sleep spent supine and oxygen desaturation index, in the third trimester, were significantly associated after BMI adjustment (B = 0.018, p = 0.04). Models did not suggest significant effects of early or late pregnancy supine sleep on growth velocity (p > 0.05).
Conclusions
Going-to-bed position predicts predominant supine sleep in less than half of women with overweight and obesity. Time spent supine throughout pregnancy correlates with measures of sleep-disordered breathing. Maternal sleep position patterns did not affect fetal growth velocity in this high-risk population, but the study was not powered to detect differences.