Sleep-disordered breathing and daytime napping are associated with maternal hyperglycemia

Association between sleep duration during pregnancy and gestational diabetes mellitus: a systematic review and meta-analysis

Objective

To systematically review studies on the correlation between sleep duration during pregnancy and gestational diabetes mellitus (GDM) and use meta-analysis to explore the correlation between the two to provide a basis for preventing GDM during pregnancy.

Methods

The search databases were China Knowledge Network (CNKI), Weipu, Wanfang, China Biomedical Literature Service System (SinoMed), Cochrane Library, Web of Science, Embase, and PubMed, and the search time was from the establishment of the above databases to July 2023. The data were statistically analyzed using STATA/MP17 and RevMan 5.3 software. Publication bias could be accurately assessed using funnel plots and Egger's test.

Results

A total of 5,197 papers were searched, and 13 studies were finally included, which included 80,259 individuals, including 3,461 patients with GDM. The comprehensive analysis showed that. Based on pooled data from prospective, cross-sectional, and case-control studies, extreme sleep duration during pregnancy was strongly associated with GDM compared with average sleep duration. The results of the prospective studies showed that both short (OR = 1.50, 95% CI: 1.07-2.10, I2 = 60.9%, p = 0.02) and long (OR = 1.28, 95% CI: 1.13-1.46, I2 = 0.0%, p < 0.0001) sleep duration increased the risk of gestational diabetes mellitus, but the harms were more pronounced with short sleep. In analyzing the association between extreme sleep duration and GDM, publication bias was found in prospective, cross-sectional, and case-control studies with moderate heterogeneity and prospective-only studies with low heterogeneity.

Conclusion

Both too short and too long sleep duration during pregnancy are strongly associated with GDM. Either too short or too long sleep duration predicts the risk of developing GDM, but the harms are more pronounced with short sleep. These findings remind us of the importance of controlling sleep duration during pregnancy and help to optimize early strategies to prevent GDM.Systematic review registration: http://www.crd.york.ac.uk/prospero, identifier [CRD42023470925].

The relationship between daytime napping and glycemic control in people with type 2 diabetes

Aim

To examine the association between napping characteristics and glycemic control in people with type 2 diabetes.

Design

This study used a cross-sectional design.

Methods

A convenience sample of people with type 2 diabetes (N=226) were included. Glycemic control was indicated by HbA1c which was measured by A1C Now®+. Napping characteristics including napping frequency, duration, timing, and type were measured by validated questionnaires. Other variables, such as insomnia, cognitive impairment, and depression were measured by the Insomnia Severity Index, Montreal Cognitive Assessment, and Patient Health Questionnaire-9, respectively. Multivariate linear regression analyses were performed.

Results

The sample consisted of 122 women (54.0%), with a median age of 67 years. Their median HbA1c was 6.8%. No significant relationship was found between napping frequency and HbA1c. Among nappers, after controlling for covariates, long napping duration (≥60 min) and morning napping were both associated with poorer glycemic control. Compared with appetitive napping, restorative napping was associated with better glycemic control.

Conclusion

Daytime napping (e.g., duration and type) is an important modifiable factor for glycemic control in people with type 2 diabetes. This study provides new insights into the relationship between napping and glucose management among people with diabetes.

Common sleep disorders in pregnancy: a review

In this review, we provide a comprehensive overview of common sleep disorders during pregnancy, including their characterization, prevalence, risk factors, and possible contribution to maternal and fetal outcomes. We conducted a quasi-systematic literature search of the MEDLINE database and identified 744 studies from 1991 through 2021, inclusive, that met our inclusion criteria. We synthesized the existing literature on sleep disorders during pregnancy and highlighted controversies, research gaps, and needed clinical developments. Our review covers a range of sleep disorders, including insomnia, obstructive sleep apnea, restless legs syndrome, and circadian rhythm disorders. We discuss the prevalence of these disorders in pregnancy and their potential impact on maternal and fetal health outcomes. We also explore the relationship between sleep disorders, pre-pregnancy comorbidities such as obesity, and pregnancy-related conditions such as gestational diabetes mellitus and preeclampsia. In addition to summarizing the existing literature on sleep disorders during pregnancy, we also highlight opportunities for further research in this area. We suggest that future studies should strive to employ validated and objective measurement tools for sleep disorders and prioritize utilization of longitudinal methods with participant follow-up through postpartum, mid-life, menopause, and beyond. We also put forward investigation into the impact of circadian rhythm disruption on reproductive physiology and early pregnancy outcomes as an area of important work. Overall, our review provides valuable insights on sleep and reproduction and into common sleep disorders during pregnancy and their potential impact on maternal and fetal health outcomes.

Self-reported sleep-disordered breathing and insomnia in association with hypertension: a community-based study in Eastern China

OBJECTIVE

We aimed to explore the associations of self-reported sleep-disordered breathing (SDB) and insomnia with hypertension based on a community-based survey among adults in Suzhou, Eastern China.

METHODS

The Suzhou Food Consumption and Health Survey was conducted from 2018 to 2019. A multistage random sampling method was used to recruit potential participants. Associations of SDB and insomnia with hypertension were examined by multivariable logistic regression models with adjustment for covariates. In addition, sensitivity analysis was used to reinforce our findings.

RESULTS

A total of 2728 participants were included in the final analysis. SDB (OR, 1.83; 95% CI, 1.44-2.34; P < 0.001) and insomnia (OR, 1.31; 95% CI, 1.04-1.65; P < 0.001) were significantly associated with prevalent hypertension after multivariable adjustments. In the subgroup analysis by age groups and sex, the association between SDB and hypertension persisted in all groups, whereas the association between insomnia and hypertension remained significant in males and different age groups. In addition, SDB was positively correlated with DBP. Notably, participants with comorbid SDB and insomnia had the highest risk for hypertension (OR, 1.95; 95% CI, 1.40-2.72; P < 0.001).

CONCLUSION

Both SDB and insomnia were associated with the prevalence of hypertension among the Chinese adults, whereas the comorbid conditions conveyed the highest risk for hypertension. Our findings provide a new insight for the potential pathogenesis of hypertension and a prevention strategy of hypertension among community adults.

Snoring and napping independently increased the serum uric acid levels and hyperuricemia risk: The Henan Rural Cohort Study

BACKGROUND AND AIMS

Evidence on the association of snoring, daily sleep duration (daytime napping and night sleep duration) with hyperuricemia (HUA) was limited, especially in the resources-poor areas. This study aimed to investigate the independent effect of snoring frequency and daily sleep duration on HUA prevalence in rural Chinese adults.

METHODS AND RESULTS

29,643 participants aged 18-79 years were included in the final cross-sectional analysis from the Henan Rural Cohort Study. Multivariate logistic regression and linear regression models with HUA and serum uric acid (SUA) levels as dependent variables were conducted, respectively. Of the 29,643 included adults, 3498 suffered from HUA. Compared to never snoring, the adjusted odds ratio (OR) and 95% confidence interval (CI) of HUA for rare snoring, occasional snoring, and habitual snoring were 1.35 (1.17, 1.56), 1.30 (1.14, 1.47), and 1.59 (1.47, 1.73), respectively (P for trend <0.001). Compared with no napping, participants who had daytime napping of 61-90 and > 91 min were associated with a 29% and 30% increase in the prevalence of HUA, respectively (P for trend <0.001). But in night sleep duration groups, no significant associations were observed. The positive associations between snoring and HUA were attenuated in people aged ≥65 and people with type 2 diabetes mellitus (both P for interaction <0.05).

CONCLUSION

Habitual snoring or longer daytime napping was independently associated with increased HUA prevalence and SUA levels in rural Chinese adults, which indicates the significance of early intervention and treatment of snoring and longer daytime napping to prevent hyperuricemia.

A Review of the Associations Between Obstructive Sleep Apnea and Gestational Diabetes Mellitus and Possible Mechanisms of Disease

Obstructive sleep apnea (OSA) usually leads to the occurrence of diabetes. Gestational diabetes mellitus (GDM) is a common gestational complication associated with adverse maternal and fetal outcomes. Increasing studies suggest that women with OSA during pregnancy may be at a significantly greater risk of developing GDM. It is crucial to explore the association between OSA and GDM and the mechanisms underlying this association. In this review, we presented a comprehensive literature review of the following: the association between OSA and GDM, the possible mechanisms of this association, and the effects of continuous positive airway pressure (CPAP) on OSA with GDM. The results showed that most authors suggested that there was an association between OSA and GDM. The intermittent hypoxemia (IH) and reduction of slow-wave sleep (SWS) may be the key to this association. IH induces the products of oxidative stress and inflammation as well as dysregulation of the hypothalamic-pituitary-adrenal, which lead to diabetes. In addition, SWS reduction in OSA enhances the inflammation by increasing the inflammatory cytokines, increases the sympathetic activation, and causes changes in leptin level, which result in the development of GDM. Additionally, whether CPAP is beneficial to GDM remains still unclear.

Sleep and physical activity from before conception to the end of pregnancy in healthy women: a longitudinal actigraphy study

BACKGROUND

Sleep and physical activity changes are common in pregnancy, but longitudinal data starting before conception are scarce. Our aim was to determine the changes of the daily total sleep time (TST) and physical activity duration (PAD) from before conception to end of pregnancies in respect of pregestational maternal factors.

METHODS

This longitudinal observational study formed part of the CONIMPREG research project and recruited healthy women planning to become pregnant. Sleep and physical activity were recorded around-the-clock for ≥4 days via actigraphy before conception and during each trimester of pregnancy. Data were adjusted according to pregestational maternal body composition, parity and age.

RESULTS

Among 123 women with eligible data, the unadjusted mean (95% confidence interval) TST increased from 415.3 min (405.5-425.2 min) before conception to 458.0 min (445.4-470.6 min) in the 1st trimester, remaining high through the 2nd and 3rd trimesters. Variation was substantial before conception (±2SD range: 307-523 min). The unadjusted mean PAD before conception was 363.7 min (±2SD range: 120-608 min), decreasing sharply to 262.1 min in the first trimester and more gradually thereafter. Vigorous and moderate activity decreased more than light activity. TST and PAD were significantly associated with age, parity, and pregestational body fat percentage; lean body mass was negatively correlated with TST. Results were generally unaffected by seasonal variations.

CONCLUSION

Marked variations were found in pregestational TST and PAD. Healthy women slept ≥30 min longer during pregnancy, while PAD decreased by ≥ 90 min in early pregnancy and continued to decrease thereafter.

Sleep Apnea and Fetal Growth Restriction (SAFER) study: protocol for a pragmatic randomised clinical trial of positive airway pressure as an antenatal therapy for fetal growth restriction in maternal obstructive sleep apnoea

INTRODUCTION

Fetal growth restriction (FGR) is a major contributor to fetal and neonatal morbidity and mortality with intrauterine, neonatal and lifelong complications. This study explores maternal obstructive sleep apnoea (OSA) as a potentially modifiable risk factor for FGR. We hypothesise that, in pregnancies complicated by FGR, treating mothers who have OSA using positive airway pressure (PAP) will improve birth weight and neonatal outcomes.

METHODS AND ANALYSIS

The Sleep Apnea and Fetal Growth Restriction study is a prospective, block-randomised, single-blinded, multicentre, pragmatic controlled trial. We enrol pregnant women aged 18-50, between 22 and 31 weeks of gestation, with established FGR based on second trimester ultrasound, who do not have other prespecified known causes of FGR (such as congenital anomalies or intrauterine infection). In stage 1, participants are screened by questionnaire for OSA risk. If OSA risk is identified, participants proceed to stage 2, where they undergo home sleep apnoea testing. Participants are determined to have OSA if they have an apnoea-hypopnoea index (AHI) ≥5 (if the oxygen desaturation index (ODI) is also ≥5) or if they have an AHI ≥10 (even if the ODI is <5). These participants proceed to stage 3, where they are randomised to nightly treatment with PAP or no PAP (standard care control), which is maintained until delivery. The primary outcome is unadjusted birth weight; secondary outcomes include fetal growth velocity on ultrasound, enrolment-to-delivery interval, gestational age at delivery, birth weight corrected for gestational age, stillbirth, Apgar score, rate of admission to higher levels of care (neonatal intensive care unit or special care nursery) and length of neonatal stay. These outcomes are compared between PAP and control using intention-to-treat analysis.

ETHICS AND DISSEMINATION

This study has been approved by the Institutional Review Boards at Washington University in St Louis, Missouri; Hadassah Hebrew University Medical Center, Jerusalem; and the University of Rochester, New York. Recruitment began in Washington University in November 2019 but stopped from March to November 2020 due to COVID-19. Recruitment began in Hadassah Hebrew University in March 2021, and in the University of Rochester in May 2021. Dissemination plans include presentations at scientific conferences and scientific publications.

TRIAL REGISTRATION NUMBER

NCT04084990.

[Sleep apnea syndrome, pregnancy and fetal condition]

OBJECTIVE

To assess fetal cardiac activity with simultaneous polysomnographic (PSG) study of pregnancy with obstructive sleep apnea syndrome (OSAS).

MATERIALS AND METHODS

Forty-nine women, aged 18-30 years, 30-34 weeks pregnant, complaining of snoring, with a positive rating in 2 and/or 3 sections of the Berlin Sleep Questionnaire were included in the study. Sixteen pregnant women with the corresponding gestational age, without complaints of snoring, made up the control group. All participants underwent PSG monitoring and fetal cardiotocography (CTG) according to standard techniques.

RESULTS

PSG results demonstrate significant changes in sleep patterns in pregnant women with OSAS. There is a significant reduction in SWS 3, REM. High AHI, accompanied by desaturation and the appearance of activation EEG- patterns of cyclic alternations are characterized the sleep of pregnant women with OSAS. Analysis of CTG results shows that the average values of the basal rhythm are statistically higher in women with OSAS than in the control group. Also, the indicators of the amplitude of the oscillations, the frequency of oscillations and the number of movements in 30 minutes are statistically significantly different. Reaction of the fetus to episodes of apnea in the form of active perturbation, changes in heart rate as bradycardia (to 105-110 beats per minute) or tachycardia (to 155-160 beats per minute) compared to basal level (140 beats per minute) are noted.

CONCLUSION

OSAS during nocturnal sleep in pregnant women causes the changes in motor activity and cardiac activity of the fetus that indicates fetal hypoxemia.

Effects of sleep duration and sleep quality in early pregnancy and their interaction on gestational diabetes mellitus

PURPOSE

To examine the association of sleep duration and quality in early pregnancy with gestational diabetes mellitus (GDM), and explore their interaction effect on GDM.

METHODS

Participants from 2 hospitals were enrolled in this case-control study between April 2018 and November 2020. Sleep duration and quality were measured using the Pittsburg Sleep Quality Index (PSQI).

RESULTS

A total of 1300 participants (396 GDM and 904 controls) were included. After adjusting for potential confounders, higher global PSQI scores or poor sleep quality were associated with GDM with odds ratios of 1.13 (95% CI 1.07, 1.19, p < 0.001) and 1.75 (95% CI 1.29, 2.38, p < 0.001), respectively; sleep duration < 7 h, 9-9.9 h and ≥ 10 h were all associated with increased GDM with odds ratios of 4.28 (95% CI 2.51, 7.31, p < 0.001), 1.69 (95% CI 1.20, 2.39, p = 0.003), and 4.42 (95% CI 3.01, 6.50, p < 0.001), respectively. In the stratified analysis based on sleep duration, the effect of poor sleep quality on GDM in the < 7 h group (OR 5.47, 95% CI 2.57, 11.64, p < 0.001) was much stronger than that in the 7-8.9 h group (OR 1.24, 95% CI 0.81, 1.91, p = 0.327), and the p value of the interaction was 0.011.

CONCLUSIONS

Poor sleep quality and short or long sleep duration in early pregnancy were all associated with GDM, and an interaction effect between short sleep duration and poor sleep quality on GDM was noted.

Obstructive Sleep Apnea Is Associated with Newly Diagnosed Gestational Diabetes Mellitus

Rationale: Sleep-disordered breathing (SDB) is associated with increased risk of adverse pregnancy outcomes, including gestational diabetes mellitus (GDM). GDM is a significant cause of maternal and infant morbidities. Assessing these risk factors concurrently may facilitate both the identification of women at GDM risk and the initiation of GDM prevention strategies.Objectives: To investigate whether SDB events, including SDB in rapid eye movement (REM) sleep and other sleep parameters, are associated with increased risk of GDM and to evaluate the performance of the models investigating associations between breathing and sleep parameters and GDM risk.Methods: In this case-control study, 46 women with newly diagnosed GDM and 46 healthy control subjects, who were individually matched for age, gestational age, body mass index, race, and parity, completed overnight polysomnographic studies and sleep questionnaires after being screened for GDM during the late-second to mid-third trimesters. Conditional logistic regression analysis was used to identify models investigating associations between risk factors and GDM risk. The Bayesian information criterion (BIC) was employed to compare models; the model with the lowest BIC is preferred.Results: Obstructive sleep apnea (OSA; defined as an apnea-hypopnea index [AHI] >5 events/h) was present in 22% of subjects with GDM and 9% of control subjects (P < 0.001). Women with OSA had a higher GDM risk (odds ratio [OR], 4.71; 95% confidence interval [CI], 1.05-21.04). In individual models, GDM risk was also significantly higher among women with higher overall AHI (events/h OR, 1.81; 95% CI, 1.01-3.27), higher AHI in REM (events/h OR, 2.09; 95% CI, 1.02-4.31), higher oxygen desaturation index greater than or equal to 4% (ODI4; events/h OR, 2.21; 95% CI, 1.03-4.73), and higher Sleep Apnea Symptom Score (OR, 2.72; 95% CI, 1.11-6.69). The percentage of non-REM sleep was significantly associated with decreased risk of GDM (percentage of non-REM sleep OR, 0.88; 95% CI, 0.78-0.99). The BIC supports the conclusion that there is a strong association between AHI in REM and GDM risk compared with the other significant models.Conclusions: SDB events, including REM-related OSA, are linked to increased GDM risk. GDM risk is also influenced by intercorrelated sleep variables.

Polysomnographic features of pregnancy: A systematic review

Symptoms of sleep disturbances are common among pregnant women and generally worsen across gestation. Pregnancy-related sleep disorders are not only associated with a poor quality of life of the affected mothers, but also with adverse perinatal outcomes, including perinatal depression, gestational diabetes, preeclampsia, and preterm birth. The current knowledge about the impact of sleep disorders during pregnancy largely derives from the results of sleep surveys conducted in various populations. However, the number of studies examining changes in objective sleep variables during pregnancy via polysomnography has progressively increased in recent years. Here we systematically reviewed the polysomnographic studies available in the literature with the aim to describe the sleep pattern and to identify possible markers of sleep disruption in pregnant women. Based on our analysis, subjective worsening of sleep quality across gestation is related to objective changes in sleep macrostructure, which become particularly evident in the third trimester. Pregnancy per se does not represent an independent risk factor for developing major polysomnography-assessed sleep disorders in otherwise healthy women. However, in women presenting predisposing factors, such as obesity or hypertension, physiological changes occurring during pregnancy may contribute to the onset of pathological conditions, especially sleep-disordered breathing, which must be carefully considered.

Sleep quality and gestational diabetes in pregnant women: a systematic review and meta-analysis

Poor sleep quality is very common among pregnant women. Gestational diabetes mellitus (GDM) has been related to various adverse maternal and neonatal outcomes. The aim of this systematic review was to examine the association between poor sleep quality and gestational diabetes risk. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search was conducted in five electronic databases from inception to February 2019. Studies that examined the relationship between sleep quality and glucose in pregnant women were screened for eligibility. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated from aggregate data using a fixed-effect model. Thirteen non-experimental studies (n = 21,194 women) were eligible for inclusion. Poor sleep quality was measured using subjective questionnaires in nine studies and objective methods (actigraphy or polysomnography) in four studies. GDM was typically diagnosed following standard guidelines. Eight studies were included in the meta-analysis for GDM. Overall, self-reported poor sleep quality was a significant risk factor for GDM (pooled OR = 1.43, 95%CI: 1.16,1.77, p = 0.001). Three studies examined the association between objective sleep quality and GDM, but no significant relationship was observed. Subjective poor sleep quality was related to an increased risk for GDM, while objectively measured sleep quality was not. This review was limited by the assessment of sleep quality. Future larger studies are warranted to examine the effects of sleep quality on glucose metabolism in pregnancy. Ideally, these studies should measure sleep quality using both validated questionnaires and objective methods. These will provide further directions for improving sleep during pregnancy and exploring its effects on glucose metabolism.

The interactive effect of habitual midday napping and nighttime sleep duration on impaired fasting glucose risk in healthy adolescents

OBJECTIVES

To investigate the association between habitual midday napping and impaired fasting glucose (IFG), and the interactive effect of napping and time in bed (TIB) at night on IFG among healthy adolescents.

METHODS

The sample comprised 625 early adolescents (12.26 ± 0.63 years old) who self-reported good health status from Jintan, China. Midday napping and nighttime sleep were measured using the Youth Self-report Sleep Questionnaire. Fasting plasma glucose was dichotomized into normal (<5.6 mmol/L) and impaired (≥5.6 mmol/L) levels. The multivariate random-effect logistic regression examined the nap-glucose relationship and the interaction between nap and TIB. Marginal effects of napping were calculated when TIB was held constant at different values.

RESULTS

Of the participants, 83.20% (n = 520) took naps and 62.28% reported average nap durations ≥31 min in the past month. Moreover, 16% (n = 101) of participants had IFG. After adjusting for covariates, early adolescents who napped 3-4 days/week (OR = 1.72, p < 0.001), 5-7 days/week (OR = 1.34, p = 0.02) or ≥31 min/nap (OR = 1.52, 1.56, p's < 0.05) were associated with increased likelihoods of IFG compared to non-nappers. There was an inverse relationship between TIB and IFG among non-nappers (OR = 0.45, p = 0.03). Interaction analyses also showed significantly increased likelihoods of IFG only among nappers with TIB ≥9 hours.

CONCLUSION

The relationship between midday napping and IFG is dependent on TIB. Midday naps may increase the risk for IFG among early adolescents who have sufficient nighttime sleep. However, further research is needed to confirm our preliminary findings.

Sleep in Pregnancy and Maternal Hyperglycemia: a Narrative Review

PURPOSE OF REVIEW

Prevalence of gestational diabetes is increasing globally and sleep may be a modifiable lifestyle factor associated with it. However, existing findings have been inconsistent.

RECENT FINDINGS

Majority of studies reviewed found a link between extreme sleep durations and elevated risk of maternal hyperglycemia. The findings with sleep-disordered breathing are less consistent. Methodological differences across studies, in terms of sleep assessment methods (subjective vs. objective), study population (low vs. high risk), classification of gestational diabetes and sleep problems, may have contributed to the inconsistent findings. Some studies also suggest the possibility of trimester-specific association between sleep and maternal hyperglycemia. Large-scale prospective studies comprising objective measurements of sleep, preferably over three trimesters and preconception, are needed to better evaluate the relationship between sleep and maternal hyperglycemia.

Delayed Lactogenesis II is Associated With Lower Sleep Efficiency and Greater Variation in Nightly Sleep Duration in the Third Trimester

BACKGROUND

Metabolic and hormonal disturbances are associated with sleep disturbances and delayed onset of lactogenesis II.

RESEARCH AIMS

The aim of this study was to measure sleep using wrist actigraphy during gestation weeks 22 and 32 to determine if sleep characteristics were associated with blood glucose, body mass index, gestational related disease, delayed onset of lactogenesis II, or work schedule.

METHODS

Demographic data were collected at study intake from primiparous women who wore a wrist actigraph during gestation weeks 22 (n = 50) and 32 (n = 44). Start and end sleep time, total nighttime sleep, sleep efficiency, wake after sleep onset, and sleep fragmentation were measured. Night to night variability was assessed with the root mean square of successive difference. Blood glucose levels, body mass index, and gestational disease data were abstracted from medical charts. Timing of lactogenesis II was determined by survey.

RESULTS

Between gestation week 22 and 32, sleep efficiency decreased and fragmentation increased (p < .05). During gestation week 32, blood glucose was negatively correlated with sleep duration, and positively related to fragmentation (p < .05). Women who experienced delayed lactogenesis II had lower sleep efficiency and greater fragmentation (p < .05), and greater night-to-night variability in sleep start and end time, efficiency, and duration during gestation week 32 (p < .05).

CONCLUSION

Women with better sleep efficiency and more stable nightly sleep time are less likely to experience delayed onset of lactogenesis II. Interventions to improve sleep may improve maternal health and breastfeeding adequacy.

A Screening Algorithm for Obstructive Sleep Apnea in Pregnancy

Rationale: Obstructive sleep apnea (OSA) is common in pregnancy and associated with maternal and fetal complications. Early detection of OSA may have important implications for maternal-fetal well-being. A screening tool combining several methods of assessment may better predict OSA among pregnant women compared with tools that rely solely on self-reported information.Objectives: To develop a screening tool combining subjective and objective measures to predict OSA in pregnant women.Methods: This study is a secondary analysis using data collected from a completed cohort of pregnant women (n = 121 during the first and n = 87 during the third trimester). Participants underwent full polysomnography and completed the Multivariable Apnea Prediction Questionnaire. The Obstructive Sleep Apnea/Hypopnea Syndrome Score and Facco apnea predictive model were obtained. Logistic regression analysis and area under the curve (AUC) were used to identify models predicting OSA risk.Results: Participants' mean age was 27.4 ± 7.0 years. The prevalence of OSA during the first and third trimester was 10.7% and 24.1%, respectively. The final model predicting OSA risk consisted of body mass index, age, and presence of tongue enlargement. During the first trimester, the AUC was 0.86 (95% confidence interval [CI], 0.76-0.96). During the third trimester, the AUC was 0.87 (95% CI, 0.77-0.96). When the first-trimester data were used to predict third-trimester OSA risk, the AUC was 0.87 (95% CI, 0.77-0.97). This model had high sensitivity and specificity when used during both trimesters. The negative posttest probabilities (probability of OSA given a negative test result) ranged from 0.03 to 0.07.Conclusions: A new model consisting of body mass index, age, and presence of tongue enlargement provided accurate screening of OSA in pregnant women, particularly African-Americans. This tool can be easily and rapidly administered in busy clinical practices without depending on patients' awareness of experiencing apnea symptoms.

Sleep Disturbances and Modulations in Inflammation: Implications for Pregnancy Health

When a woman becomes pregnant, there is a vast series of physiological, vascular, and psychological changes. Among the most commonly reported changes are those involving sleep. Pregnant women report that their ability to maintain sleep and acquire continuous refreshing sleep is impaired during the perinatal period as compared to the non-pregnant period. A growing literature supports the hypothesis that disturbed sleep (which comes in many forms) during the perinatal period is associated with an increased risk of adverse maternal, delivery, and infant outcomes. Among the suggested biological pathways linking sleep and adverse outcomes are disturbances in the immune and hormonal systems. The following paper will discuss (1) the various sleep processes that are commonly disturbed during the perinatal period and the methods used to collect sleep data; (2) the evidence linking sleep to adverse outcomes; and (3) how one specific biological pathway, the immune system, likely mediates these associations. The goal of this paper is to clarify the role that sleep disturbance has during pregnancy.

Relationship Between Sleep Quality, Depression Symptoms, and Blood Glucose in Pregnant Women

Sleep quality during pregnancy affects maternal/child health. We aimed to assess changes in sleep quality during pregnancy and determine its relationship to maternal mood, blood glucose, and work schedule among primiparous women. We conducted a prospective/longitudinal/observational study. Ninety-two pregnant women were recruited from Midwestern hospital. Mood and sleep quality data were collected using Edinburgh Postnatal Depression Scale/Pittsburgh Sleep Quality Index at Gestational Weeks 22 and 32. Forty-three women completed the study. Twenty-six women (63%) were African American and the mean age was 23.64 ( SD = 3.82) years. Rate of poor sleep quality increased during pregnancy with 25% of women had scores indicative of depression symptoms. Poor sleep quality score was related to mood scores ( p < .05) and work schedule. Blood glucose was not significantly related to sleep duration. In conclusion, poor sleep quality during pregnancy was associated with poor mood and work schedule, suggesting that interventions targeting mental health and lifestyles are needed.

Obstructive sleep apnea in pregnancy: performance of a rapid screening tool

PURPOSE

The Sleep Apnea Symptom Score (SASS) has been commonly used to assess obstructive sleep apnea (OSA). The aim of this study was to examine the psychometric properties of the SASS and the predictive value of SASS incorporating bedpartner-reported information in identifying OSA in pregnant women.

METHODS

A cohort of healthy pregnant women completed the SASS and Pittsburgh Sleep Quality Index. Participants underwent overnight laboratory polysomnography (PSG) monitoring. Reliability and validity of the SASS were evaluated. A multivariable predictive model, incorporating the SASS score along with BMI, age, and bedpartner-reported information, was developed to assess the risk for OSA (AHI ≥ 5 events/h). Receiver operating characteristic curves for OSA were constructed to evaluate the sensitivity and specificity of the predictive model.

RESULTS

A total of 126 and 105 participants completed the PSG during the first and third trimester, respectively. The SASS demonstrated adequate validity and acceptable reliability (Cronbach's α = 0.72 during the third trimester). When the combined model consisting of SASS, age, BMI, and bedpartner-reported information was used, the area under the curve for AHI ≥ 5 for the first and third trimester was 0.781 (95%CI 0.648, 0.914) and 0.842 (95%CI 0.732, 0.952), respectively; the sensitivity/specificity was 76.9%/72.4% and 82.4%/78.0%, respectively.

CONCLUSIONS

The SASS alone has acceptable reliability and validity, but limited predictive values. A new tool, combining the SASS and other patient characteristics (i.e., age, BMI, and bedpartner-reported snoring and breathing pauses), demonstrated improved sensitivity and specificity, and thus may have greater utility in clinical practice for predicting OSA in pregnant women.

Changes in Sleep Characteristics and Breathing Parameters During Sleep in Early and Late Pregnancy

STUDY OBJECTIVES

Few studies have objectively evaluated sleep characteristics during pregnancy or investigated the relationship between altered spectral electroencephalogram (EEG) bands and sleep-disordered breathing (SDB). The study aimed to describe changes in sleep as measured by polysomnography (PSG) and spectral EEG bands during pregnancy and to examine the relationship between delta power in non-rapid eye movement (NREM) sleep and SDB.

METHODS

This is a secondary analysis of a prospective study. One hundred twenty-three women underwent full PSG in early pregnancy, and 97 repeated PSG in late pregnancy. Spectral analysis of the EEG in NREM sleep was performed. We used linear and logistic mixed-model regression to analyze the sleep measures and linear regression to explore the association between delta power and apnea-hypopnea index (AHI) changes during pregnancy.

RESULTS

In late pregnancy, women had shorter sleep duration, poorer sleep efficiency, more awakenings, more stage N2 sleep, less slow wave sleep, less REM sleep, higher AHI, and higher periodic limb movement index compared to early pregnancy. The percentage of stage N1 sleep, sleep latency, REM sleep latency, and arousal index frequency did not change. Regarding EEG-spectra, delta and theta powers decreased, but beta-2 power increased during pregnancy. In multivariable analyses, greater reduction of delta power was associated with larger increases in AHI (β [95% confidence interval] = -0.038 [-0.073, -0.002], P = .040). Estimates suggest that each one-unit increase in AHI reduces delta power by 4% in late pregnancy.

CONCLUSIONS

PSG-measured sleep characteristics change during pregnancy. Delta power decreases when the severity of SDB increases during pregnancy.

COMMENTARY

A commentary on this article appears in this issue on page 1095.

The role of sleep duration and sleep disordered breathing in gestational diabetes mellitus

Many women experience sleep problems during pregnancy. This includes difficulty initiating and maintaining sleep due to physiologic changes that occur as pregnancy progresses, as well as increased symptoms of sleep-disordered breathing (SDB). Growing evidence indicates that sleep deficiency alters glucose metabolism and increases risk of diabetes. Poor sleep may exacerbate the progressive increase in insulin resistance that normally occurs during pregnancy, thus contributing to the development of maternal hyperglycemia. Here, we critically review evidence that exposure to short sleep duration or SDB during pregnancy is associated with gestational diabetes mellitus (GDM). Several studies have found that the frequency of GDM is higher in women exposed to short sleep compared with longer sleep durations. Despite mixed evidence regarding whether symptoms of SDB (e.g., frequent snoring) are associated with GDM after adjusting for BMI or obesity, it has been shown that clinically-diagnosed SDB is prospectively associated with GDM. There are multiple mechanisms that may link sleep deprivation and SDB with insulin resistance, including increased levels of oxidative stress, inflammation, sympathetic activity, and cortisol. Despite emerging evidence that sleep deficiency and SDB are associated with increased risk of GDM, it has yet to be demonstrated that improving sleep in pregnant women (e.g., by extending sleep duration or treating SDB) protects against the development of hyperglycemia. If a causal relationship can be established, behavioral therapies for improving sleep can potentially be used to reduce the risk and burden of GDM.

Risk of glucose intolerance and gestational diabetes mellitus in relation to maternal habitual snoring during early pregnancy

Background

Obstructive sleep apnea (OSA) or habitual snoring is known to be associated with impaired glucose tolerance and type 2 diabetes among both men and non-pregnant women. We examined the association of habitual snoring during early pregnancy with risk of impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM).

Methods

A cohort of 1,579 women was interviewed during early pregnancy. We collected information about snoring frequency during early pregnancy. Results from screening and diagnostic tests for IGT and GDM were abstracted from medical records. Multivariate logistic regression models were fitted to estimate odds ratios (OR) and 95% confidence intervals (95% CI) of IGT and GDM associated with snoring in early pregnancy.

Results

Overall, women who snored “most or all of the time” had a 2.1-fold increased odds of IGT (OR 2.10; 95% CI 1.31–3.35) and a 2.5-fold increased odds of GDM (OR 2.50; 95% CI 1.34–4.67) as compared with women who never snored. Compared with lean women (pre-pregnancy body mass index (BMI) <25 kg/m²) who did not snore, lean snorers had a 2-fold increased odds of GDM (OR = 1.99, 95% CI: 1.07–3.68). The odds of GDM risk was particularly elevated among overweight women (BMI ≥ 25 kg/m²) who snored (OR = 5.01; 95% CI 2.71–9.26). However, there was no evidence of an interaction between overweight and snoring with GDM risk (p-value = 0.144).

Conclusions

These findings, if confirmed, may have important implications for tailoring prenatal care for overweight pregnant women, and /or those with a history of habitual snoring in early pregnancy.

Obstructive sleep apnea and diet-controlled gestational diabetes

BACKGROUND

Obstructive sleep apnea (OSA) was shown to be associated with gestational diabetes mellitus (GDM). However, prevalence of OSA in GDM women, its relationship to metabolic control, and predictive factors have not been studied.

MATERIAL AND METHODS

Eighty-two obese pregnant women with diet-controlled GDM between 24 and 34 weeks of gestation participated. The Berlin questionnaire was used to assess OSA symptoms. OSA was diagnosed using an overnight monitor. Fasting glucose and hemoglobin A1c (HbA1c) were obtained. Those with OSA underwent meal tolerance test (MTT) to assess their metabolic parameters. Classification tree analysis was used to develop a screening tool for OSA.

RESULTS

At a median gestational age of 29 weeks, OSA was diagnosed in 52.4% of the women, with a median apnea hypopnea index of 9.4 (interquartile range 6.4, 12.4). More severe OSA was significantly correlated with higher fasting glucose but not HbA1c. For those with OSA, sleep parameters related to oxygen desaturation significantly correlated with higher fasting insulin resistance and more severe β-cell dysfunction, as evaluated by MTT. A screening tool involving two variables, neck circumference and Berlin Questionnaire score, was developed. The sensitivity and specificity were 86% and 51%, respectively. The overall accuracy was 70%.

CONCLUSION

OSA is prevalent in obese pregnant women with diet-controlled GDM in the late second to early third trimester. OSA severity, especially the degree of oxygen desaturation, correlated with fasting glucose, insulin resistance, and β-cell function. A simple screening tool involving the Berlin Questionnaire and neck circumference can aid in predicting OSA in this patient group.

Maternal Habitual Midday Napping Duration and Frequency are Associated with High Birthweight

Habitual midday napping is a common habit in China, especially for pregnant women. The purpose of this study was to examine whether duration and frequency of maternal habitual midday napping were associated with high birthweight (HBW). A total of 10,482 participants from Healthy Baby Cohort were include in our analysis. The information of the mothers and their infants were abstracted from medical records, or obtained from questionnaire. Logistic regression models were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of habitual midday napping duration and frequency with HBW. Of the participants, 8,705 (83.0%) reported having habitual midday napping. Duration and frequency of napping had a positive association with HBW without adjustment. After controlling for potential confounders, increasing risk of HBW was observed in participants who napped 1.5–2 hours (OR, 1.50, 95% CI, 1.14, 1.98), and ≥2 hours (OR, 1.35, 95% CI, 1.03, 1.78) compared with no habitual midday napping. Participants who took naps ≥5 days/week had a higher risk of HBW (OR, 1.37, 95% CI, 1.07, 1.77) compared with the women without naps. This suggests that longer (≥1.5 hours) and more frequent (≥5 days/week) maternal habitual midday napping were associated with an increased risk of HBW.

Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients With Obstructive Sleep Apnea

Supplemental Digital Content is available in the text.

The purpose of the Society of Anesthesia and Sleep Medicine guideline on preoperative screening and assessment of adult patients with obstructive sleep apnea (OSA) is to present recommendations based on the available clinical evidence on the topic where possible. As very few well-performed randomized studies in this field of perioperative care are available, most of the recommendations were developed by experts in the field through consensus processes involving utilization of evidence grading to indicate the level of evidence upon which recommendations were based. This guideline may not be appropriate for all clinical situations and all patients. The decision whether to follow these recommendations must be made by a responsible physician on an individual basis. Protocols should be developed by individual institutions taking into account the patients’ conditions, extent of interventions and available resources. This practice guideline is not intended to define standards of care or represent absolute requirements for patient care. The adherence to these guidelines cannot in any way guarantee successful outcomes and is rather meant to help individuals and institutions formulate plans to better deal with the challenges posed by perioperative patients with OSA. These recommendations reflect the current state of knowledge and its interpretation by a group of experts in the field at the time of publication. While these guidelines will be periodically updated, new information that becomes available between updates should be taken into account. Deviations in practice from guidelines may be justifiable and such deviations should not be interpreted as a basis for claims of negligence.

A longitudinal study of sleep duration in pregnancy and subsequent risk of gestational diabetes: findings from a prospective, multiracial cohort

BACKGROUND

Both short and prolonged sleep duration have been linked to impaired glucose metabolism. Sleep patterns change during pregnancy, but prospective data are limited on their relation to gestational diabetes.

OBJECTIVE

We sought to prospectively examine the trimester-specific (first and second trimester) association between typical sleep duration in pregnancy and subsequent risk of gestational diabetes, as well as the influence of compensatory daytime napping on this association.

STUDY DESIGN

In the prospective, multiracial Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singleton Cohort, 2581 pregnant women reported their typical sleep duration and napping frequency in the first and second trimesters. Diagnosis of gestational diabetes (n = 107; 4.1%) was based on medical records review. Adjusted relative risks with 95% confidence intervals for gestational diabetes were estimated with Poisson regression, adjusting for demographics, prepregnancy body mass index, and other risk factors.

RESULTS

From the first and second trimester, sleep duration and napping frequency declined. Sleeping duration in the second but not first trimester was significantly related to risk of gestational diabetes. The association between second-trimester sleep and gestational diabetes differed by prepregnancy obesity status (P for interaction = .04). Among nonobese but not obese women, both sleeping >8-9 hours or <8-9 hours were significantly related to risk of gestational diabetes: 5-6 hours (adjusted relative risk, 2.52; 95% confidence interval, 1.27-4.99); 7 hours (adjusted relative risk, 2.01; 95% confidence interval, 1.09-3.68); or ≥10 hours (adjusted relative risk, 2.17; 95% confidence interval, 1.01-4.67). Significant effect modification by napping frequency was also observed in the second trimester (P for interaction = .03). Significant and positive association between reduced sleep (5-7 hours) and gestational diabetes was observed among women napping rarely/never (adjusted relative risk, 2.48; 95% confidence interval, 1.20-5.13), whereas no comparable associations were observed among women napping most/sometimes.

CONCLUSION

Our data suggest a U-shaped association between sleep duration and gestational diabetes, and that napping and prepregnancy obesity status may modify this association.

Late gestational intermittent hypoxia induces metabolic and epigenetic changes in male adult offspring mice

KEY POINTS

Late gestation during pregnancy has been associated with a relatively high prevalence of obstructive sleep apnoea (OSA). Intermittent hypoxia, a hallmark of OSA, could impose significant long-term effects on somatic growth, energy homeostasis and metabolic function in offspring. Here we show that late gestation intermittent hypoxia induces metabolic dysfunction as reflected by increased body weight and adiposity index in adult male offspring that is paralleled by epigenomic alterations and inflammation in visceral white adipose tissue. Fetal perturbations by OSA during pregnancy impose long-term detrimental effects manifesting as metabolic dysfunction in adult male offspring.

ABSTRACT

Pregnancy, particularly late gestation (LG), has been associated with a relatively high prevalence of obstructive sleep apnoea (OSA). Intermittent hypoxia (IH), a hallmark of OSA, could impose significant long-term effects on somatic growth, energy homeostasis, and metabolic function in offspring. We hypothesized that IH during late pregnancy (LG-IH) may increase the propensity for metabolic dysregulation and obesity in adult offspring via epigenetic modifications. Time-pregnant female C57BL/6 mice were exposed to LG-IH or room air (LG-RA) during days 13-18 of gestation. At 24 weeks, blood samples were collected from offspring mice for lipid profiles and insulin resistance, indirect calorimetry was performed and visceral white adipose tissues (VWAT) were assessed for inflammatory cells as well as for differentially methylated gene regions (DMRs) using a methylated DNA immunoprecipitation on chip (MeDIP-chip). Body weight, food intake, adiposity index, fasting insulin, triglycerides and cholesterol levels were all significantly higher in LG-IH male but not female offspring. LG-IH also altered metabolic expenditure and locomotor activities in male offspring, and increased number of pro-inflammatory macrophages emerged in VWAT along with 1520 DMRs (P < 0.0001), associated with 693 genes. Pathway analyses showed that genes affected by LG-IH were mainly associated with molecular processes related to metabolic regulation and inflammation. LG-IH induces metabolic dysfunction as reflected by increased body weight and adiposity index in adult male offspring that is paralleled by epigenomic alterations and inflammation in VWAT. Thus, perturbations to fetal environment by OSA during pregnancy can have long-term detrimental effects on the fetus, and lead to persistent metabolic dysfunction in adulthood.

Sleep Quality and Nocturnal Sleep Duration in Pregnancy and Risk of Gestational Diabetes Mellitus

Study Objectives

To examine the influence of maternal sleep quality and nocturnal sleep duration on risk of gestational diabetes mellitus (GDM) in a multiethnic Asian population.

Methods

A cohort of 686 women (376 Chinese, 186 Malay, and 124 Indian) with a singleton pregnancy attended a clinic visit at 26-28 weeks of gestation as part of the Growing Up in Singapore Towards healthy Outcomes mother-offspring cohort study. Self-reported sleep quality and sleep duration were assessed using the Pittsburgh Sleep Quality Index (PSQI). GDM was diagnosed based on a 75-g oral glucose tolerance test administered after an overnight fast (1999 WHO criteria). Multiple logistic regression was used to model separately the associations of poor sleep quality (PSQI score > 5) and short nocturnal sleep duration (<6 h) with GDM, adjusting for age, ethnicity, maternal education, body mass index, previous history of GDM, and anxiety (State-Trait Anxiety Inventory score).

Results

In the cohort 296 women (43.1%) had poor sleep quality and 77 women (11.2%) were categorized as short sleepers; 131 women (19.1%) were diagnosed with GDM. Poor sleep quality and short nocturnal sleep duration were independently associated with increased risk of GDM (poor sleep, adjusted odds ratio [OR] = 1.75, 95% confidence interval [CI] 1.11 to 2.76; short sleep, adjusted OR = 1.96, 95% CI 1.05 to 3.66).

Conclusions

During pregnancy, Asian women with poor sleep quality or short nocturnal sleep duration exhibited abnormal glucose regulation. Treating sleep problems and improving sleep behavior in pregnancy could potentially reduce the risk and burden of GDM.

Effects of supervised aerobic and strength training in overweight and grade I obese pregnant women on maternal and foetal health markers: the GESTAFIT randomized controlled trial

BACKGROUND

During pregnancy, a sedentary lifestyle may have negative consequences on maternal and foetal health status. The main objective of this project is to assess the effects of an exercise intervention in overweight and grade I obese pregnant on maternal and foetal health markers.

METHODS/DESIGN

The present study aims to recruit 60 overweight and grade I obese women interested in participating in an exercise intervention program from the 17th gestational week until delivery. Women will be randomized to either an exercise (three 60-min sessions/week of combined aerobic and strength training and pelvic floor exercises), or usual care (control) group (30 women per group). The primary outcome measures are maternal weight gain, and maternal and neonatal glycaemic profile. Secondary outcome measures are: i) perinatal obstetric records; i) body composition; iii) dietary patterns; iv) physical fitness; v) low-back pain; vi) objectively measured physical activity and sedentary behaviour; vii) haematology and biochemical analyses; viii) oxidative stress; ix) pro- and anti-inflammatory markers; x) bone health biomarkers; xi) sleep quality; xii) mental health, quality of life and positive health.

DISCUSSION

The findings of this project will help to identify strategies for primary prevention and health promotion based on this exercise-based intervention program among overweight and grade I obese pregnant women.

TRIAL REGISTRATION

NCT02582567 ; Date of registration: 20/10/2015.

Cross-sectional and longitudinal associations between sleep and health-related quality of life in pregnant women: A prospective observational study

BACKGROUND

Sleep disturbances are common in women, especially during pregnancy. Previous studies have confirmed the importance of sleep disturbances as a risk factor of adverse pregnancy outcomes and the need for screening and treatment of inadequate sleep. These reports, however, did not examine health-related quality of life which may be affected by sleep long before adverse clinical consequences are detectable in women during pregnancy.

OBJECTIVES

To examine the cross-sectional and longitudinal association between sleep and health-related quality of life in pregnant women.

DESIGN

A prospective observational study.

SETTING

A university-affiliated hospital in Taiwan and participants' homes.

PARTICIPANTS

A total of 164 pregnant women completed questionnaires and wore a wrist actigraphy monitor for 7 days each trimester.

METHODS

Objective sleep was measured by actigraphy, subjective sleep was measured by the Pittsburgh Sleep Quality Index, and health-related quality of life was measured using the SF-12v2 questionnaire across three trimesters. Multiple linear regression analyses were performed to evaluate the cross-sectional and longitudinal associations between sleep and health-related quality of life.

RESULTS

Sixty-four (39.0%) women consistently had an average sleep efficiency<85% by actigraphy and 40 (24.4%) had a Pittsburgh Sleep Quality Index global score>5 in all three trimesters. Cross-sectionally, more actigraphic daytime sleep (p=0.04) and better subjective sleep quality (p<0.01) were associated with better physical health-related quality of life in first-trimester pregnant women. Better actigraphic sleep efficiency (p=0.04) and better subjective sleep quality (p<0.01) were associated with better mental health-related quality of life in second-trimester pregnant women. Longer actigraphic total nighttime sleep (p<0.01) and better subjective sleep quality (p<0.01) were associated with better mental health-related quality of life in third-trimester pregnant women. Longitudinally, first-trimester actigraphic total nighttime sleep (p<0.05) and subjective sleep quality (p<0.01) predicted mental health-related quality of life in the second and third trimester.

CONCLUSIONS

Sleep disturbances are a highly prevalent and persistent problem in pregnant women. Adequate sleep is essential for women at all pregnancy stages and improving nocturnal sleep quantity and quality in early gestation is of utmost importance for an optimal health-related quality of life later in pregnancy.

Minimal Effect of Daytime Napping Behavior on Nocturnal Sleep in Pregnant Women

STUDY OBJECTIVES

To assess whether daytime naps negatively impact nocturnal sleep.

DESIGN

Longitudinal, prospective cohort design.

PARTICIPANTS

161 pregnant women recruited and evaluated in early gestation (10-20 weeks).

MEASUREMENTS AND RESULTS

Daily sleep information was collected in three 2-week periods (10-12, 14-16, and 18-20 weeks gestation) with a daily sleep diary and an actigraph. The average number of naps, as well as the average length of each nap, were calculated from sleep diaries. Women were categorized first as non nappers (0 naps/2-week period), moderate nappers (1-3 naps/2-week period), or frequent nappers (≥ 4 naps/2-week period). Then, based on the average nap length, they were categorized as short (< 90 min) or long (≥ 90 min) nappers. Nocturnal sleep parameters included SOL, WASO, SE, and TST. SAS procedure MIXED was used for modeling the main effects of nap group and time, and time by nap group interactions. Women who took naps had a decrease in diary-assessed nocturnal TST, but not actigraphy-assessed TST. This observation was group- and time-specific. There were no other group differences. Women who napped ≥ 90 min had poorer diary-assessed SE and lower diary-assessed TST than those who took shorter naps. Length of nap was not associated with any other sleep measures.

CONCLUSIONS

The number of daytime naps have minimal impact on nocturnal sleep parameters; however, long nappers did exhibit modestly impaired sleep continuity and sleep quality. Overall, we propose that daytime naps provide a beneficial countermeasure to the sleep disruption commonly reported by pregnant women. This may be clinically beneficial given that sleep continuity and quality are important correlates of pregnancy outcomes.

COMMENTARY

A commentary on this article appears in this issue on page 593.

Adherence to physical activity guidelines in mid-pregnancy does not reduce sedentary time: an observational study

Background

Physical activity (PA) interventions designed to prevent prenatal complications have focused on increasing moderate PA yielding conflicting results. Minimal attention has focused on the evaluation of sleep, sedentary behavior (SB), light activity or total daily PA during pregnancy. The purpose of this prospective, longitudinal study was to 1) objectively quantify and compare habitual PA and SB during the 2^nd and 3^rd trimester; and 2) evaluate differences in activity patterns for women meeting prenatal PA guidelines versus those that did not.

Methods

Forty-six participants wore 2 PA monitors (SenseWear® Mini and activPAL™) during week 18 and week 35 of pregnancy. We compared differences in sleep duration, postural allocation, daily steps, and PA between the 2^nd and 3^rd trimester and for women who met and did not meet PA guidelines.

Results

During the 2^nd trimester, 30% of the women’s day (24-hours) was total sleep; 52% SB; 13% light; 3% moderate; and 0% vigorous PA. Light (P = 0.05), vigorous (P = 0.02), and moderate-vigorous PA (MET-minutes; P = 0.02), decreased with a trend in increased SB (P = 0.07). Activity of other intensities and sleep duration did not significantly change. Only 39% and 37% of participants slept between 7–9 hours/night at week 18 and 35, respectively. Forty-six percent (n = 21) and 28% (n = 13) of participants met prenatal PA guidelines during the 2^nd and 3^rd trimester, respectively. At week 18, no differences in total sleep, SB, or light PA existed for women who met PA guidelines versus those who did not; total PA was significantly greater for women who met guidelines. At week 35, women that met PA guidelines had significantly less SB (P < 0.005) than women who did not.

Conclusions

This study demonstrates that pregnant women spend the majority of their day in SB. Significant reductions in total activity across pregnancy may be attributed, in part to shifts in light PA and increased SB. Based on the lifestyle of our sample, regardless of meeting PA guidelines in mid-pregnancy, no significant difference exists in time spent in SB, however meeting PA recommendations in late pregnancy may reduce SB. Future interventions should target reducing SB by increasing light and moderate PA beyond volitional exercise.

Does Circadian Disruption Play a Role in the Metabolic-Hormonal Link to Delayed Lactogenesis II?

Breastfeeding improves maternal and child health. The American Academy of Pediatrics recommends exclusive breastfeeding for 6 months, with continued breastfeeding for at least 1 year. However, in the US, only 18.8% of infants are exclusively breastfed until 6 months of age. For mothers who initiate breastfeeding, the early post-partum period sets the stage for sustained breastfeeding. Mothers who experience breastfeeding problems in the early post-partum period are more likely to discontinue breastfeeding within 2 weeks. A major risk factor for shorter breastfeeding duration is delayed lactogenesis II (DLII; i.e., onset of milk "coming in" more than 72 h post-partum). Recent studies report a metabolic-hormonal link to DLII. This is not surprising because around the time of birth the mother's entire metabolism changes to direct nutrients to mammary glands. Circadian and metabolic systems are closely linked, and our rodent studies suggest circadian clocks coordinate hormonal and metabolic changes to support lactation. Molecular and environmental disruption of the circadian system decreases a dam's ability to initiate lactation and negatively impacts milk production. Circadian and metabolic systems evolved to be functional and adaptive when lifestyles and environmental exposures were quite different from modern times. We now have artificial lights, longer work days, and increases in shift work. Disruption in the circadian system due to shift work, jet-lag, sleep disorders, and other modern life style choices are associated with metabolic disorders, obesity, and impaired reproduction. We hypothesize that DLII is related to disruption of the mother's circadian system. Here, we review literature that supports this hypothesis, and describe interventions that may help to increase breastfeeding success.

The potential value of sleep hygiene for a healthy pregnancy: a brief review

The quality of the intrauterine environment influences maternal-fetal health and also offspring predisposition to obesity and cardiometabolic disease later in life. Several determinants, including but not limited to pregravid obesity and excessive gestational weight gain, alter the developmental milieu, fetal growth, and child obesity risk. However, the role of sleep and its relationship to healthy pregnancy is not fully established. Given the host of psychosocial and physiological complications associated with childhood obesity, targeting the gestational period is purported to be an opportune time for preventive intervention. Many longitudinal studies suggest that short sleep duration is a risk factor for the development of impaired glycemia and obesity. However, there is a dearth of information concerning the role of sleep hygiene and its role in a healthy pregnancy. Reports note disrupted and poorer quality of sleep during gestation and highlight an association between reduced sleep and risk of gestational diabetes mellitus. Given the lack of well-designed human trials assessing the value of sleep and healthy pregnancy outcomes, this review summarizes current evidence which suggests that incorporating sleep recommendations and utilizing time management strategies that encourage a healthful night 's sleep may improve the health of the mom and the baby.

A systematic review and quantitative assessment of sleep-disordered breathing during pregnancy and perinatal outcomes

PURPOSE

Previous investigations have suggested a strong association between sleep-disordered breathing (SDB) during pregnancy and perinatal outcomes. However, the results of the following replication studies were not always concordant. Therefore, this meta-analysis was conducted to evaluate the more reliable estimate.

METHODS

A systematic literature search was performed on PubMed, Springer Link, and EMBASE to identify all eligible studies published before August 2013. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed or random effects model.

RESULTS

A total of 24 publications met the inclusion criteria and were included in this meta-analysis. Findings demonstrated that moderate-to-severe SDB during pregnancy was associated with gestational diabetes mellitus (OR=1.78; 95% CI, 1.29 to 2.46), pregnancy-related hypertension (OR=2.38; 95% CI, 1.63 to 3.47), preeclampsia (OR=2.19; 95% CI, 1.71 to 2.80), preterm delivery (OR=1.98; 95% CI, 1.59 to 2.48), low birth weight (OR=1.75; 95% CI, 1.33 to 2.32), neonatal intensive care unit (NICU) admission (OR=2.43; 95% CI, 1.61 to 3.68), intrauterine growth restriction (OR=1.44; 95% CI, 1.22 to 1.71), and Apgar score of <7 at 1 min (OR=1.78; 95% CI, 1.10 to 2.91) based on all studies but not gestational age and birth weight.

CONCLUSIONS

This meta-analysis revealed that moderate-to-severe SDB during pregnancy may be associated with most of adverse perinatal outcomes. Further well-designed studies are warranted to confirm our findings.

The relationship and potential mechanistic pathways between sleep disturbances and maternal hyperglycemia

This paper reviews recent work investigating the influence of sleep disturbances on maternal hyperglycemia, particularly gestational diabetes mellitus (GDM). The incidence and prevalence of hyperglycemia are increasing worldwide, which is cause for concern because GDM and even mild hyperglycemia are associated with adverse pregnancy outcomes. A better understanding of sleep-related risk factors for maternal hyperglycemia is an important health matter. Evidence demonstrates associations between sleep disturbances, especially sleep-disordered breathing, and hyperglycemia, but causal effects and the underlying mechanisms linking these conditions have not been fully elucidated. Subjective sleep assessments show associations between sleep disturbances and maternal hyperglycemia. There are, however, few studies using objective measures to support these findings. Large prospective studies are required to examine causal relationships between sleep disturbances and maternal hyperglycemia. There is also a need for smaller mechanistic studies to understand the pathophysiology. Furthermore, interventional studies are required to address whether improvement of sleep parameters can prevent/decrease the risk of developing maternal hyperglycemia. Taken together, the data suggests that sleep disturbances during pregnancy are important to identify and manage in order to minimize maternal hyperglycemia and GDM, and improve maternal and fetal well-being.

Objectively measured sleep duration and hyperglycemia in pregnancy

OBJECTIVE

Our primary purpose was to assess the impact of objectively measured nighttime sleep duration on gestational glucose tolerance. We additionally examined associations of objectively measured daytime sleep duration and nap frequency on maternal glycemic control.

METHODS

Sixty-three urban, low-income, pregnant women wore wrist actigraphs for an average of 6 full days in mid-pregnancy prior to screening for hyperglycemia using the 1-h oral glucose tolerance test (OGTT). Correlations of nighttime and daytime sleep durations with 1-h OGTT values were analyzed. Multivariable logistic regression was used to evaluate independent associations between sleep parameters and hyperglycemia, defined as 1-h OGTT values ≥130 mg/dL.

RESULTS

Mean nighttime sleep duration was 6.9±0.9 h which was inversely correlated with 1-h OGTT values (r=-0.28, P=.03). Shorter nighttime sleep was associated with hyperglycemia, even after controlling for age and body mass index (adjusted odds ratio [OR], 0.2 [95% confidence interval {CI}, 0.1-0.8]). There were no associations of daytime sleep duration and nap frequency with 1-h OGTT values or hyperglycemia.

CONCLUSIONS

Using objective measures of maternal sleep time, we found that women with shorter nighttime sleep durations had an increased risk for gestational hyperglycemia. Larger prospective studies are needed to confirm our negative daytime sleep findings.

Obstructive Sleep Apnoea in Pregnancy - More Questions than Answers

The role of obstructive sleep apnoea (OSA) in pregnancy is not well studied, but an increasing body of literature appears to indicate that there may be adverse maternal and foetal health effects of the disease. OSA is associated with a twofold risk of pre-eclampsia. The small size of the existing investigations still leave unanswered questions about the consequences of OSA as it relates to some other clinically relevant outcomes such as eclampsia, stillbirth and maternal mortality. A consistent body of literature has emerged demonstrating an increased risk of insulin resistance and diabetes associated with OSA. However, among pregnant women, the association appears to be related to short sleep duration. Well-designed and adequately powered studies are needed to further delineate the role of OSA and sleep duration on pregnancy outcome and the mechanisms of those effects.