Performance of screening questionnaires for obstructive sleep apnea during pregnancy: A systematic review and meta-analysis

Obstructive sleep apnea in pregnancy: A review of the literature from the obstetrics practitioner's view and a proposed clinical approach

Obstructive sleep apnea (OSA) is a frequent condition during pregnancy and its occurrence is increased in obese women. There are growing concerns about both pre-existing OSA and the development of gestational OSA and their effect on maternal pregnancy outcomes, fetal development, and even early childhood. A strong body of research has revealed maternal complications of OSA, but far fewer studies explore its impact on the developing fetus, highlighting an important area of future research. As evidence in both areas mounts about the negative reproductive impact of OSA, studies have emerged that explore the limitations of current diagnostic criteria and screening tools for this disorder in pregnancy which, in turn, limit the practitioner's ability to appropriately refer patients for OSA diagnosis and treatment. This expert review summarizes the current data regarding OSA screening tools in pregnancy, the limitations of these tools, and available OSA treatments and their efficacies. Our objective is to develop recommendations for how to best screen and manage OSA in pregnancy. We conclude that improved understanding of available tools and treatments will allow the obstetric practitioner to better counsel patients and help mitigate the deleterious effects of OSA on mother and fetus. We herein propose a clinical approach for the screening and management of OSA in pregnancy.

Patient preference of level I, II and III sleep diagnostic tests to diagnose obstructive sleep apnoea among pregnant women in early to mid-gestation

PURPOSE

There is a paucity of data on preferences for obstructive sleep apnoea (OSA) diagnostic tests during pregnancy. Simple test completion rates fail to capture patient preference or experience of completing sleep diagnostic tests. We assessed preference, ease of use, convenience, and the repeatability of level I, II and III sleep diagnostic tests, using questionnaires, in pregnant women in early to mid-gestation.

METHODS

Pregnant women with signs or symptoms of OSA, or at high risk of cardiometabolic disorders of pregnancy completed level I, II and III sleep studies by 24 weeks gestation. Participants then completed a questionnaire to rank test preference. Additional questionnaires assessed ease of use, convenience, and acceptability to repeat test, using 5-point Likert scale questions, yes/no response and optional linked text fields.

RESULTS

Of fifty-two consented participants, 43 completed any questionnaire (mean age 32.7 ± 5.4 years, BMI 32.7 ± 5.4, median gestation at Level I polysomnography (PSG) of 14.2 weeks (interquartile range (IQR) 13.5-17.6)). Of the 29 respondents who completed test ranking questionnaire, level III was the preferred test ((n = 21 / 29, 75%)), followed by level 1 (n = 6 / 29, 20.7%) and level II (n = 2 / 29, 7.1%) (p for diff < 0.001). Level III was reported the easiest test (very easy to complete) (n = 16, 51.6%), followed by level I(n = 10, 33.3%), and level II (n = 9, 9.1%) (p for diff < 0.001)). Level III was reported most convenient test (very convenient to complete) (n = 16, 51.6%), followed by level I (n = 4, 13.3%) and level II (n = 4, 13.3%) (p for diff < 0.001)). Level III was reported most acceptable to repeat (very acceptable to repeat) (n = 13, 41.9%), followed by level I (n = 3, 10.0%) and level II (n = 3, 10.0%) (p for diff < 0.001)).

CONCLUSION

Pregnant women being assessed for OSA by 24 weeks gestation preferred to undertake level III sleep studies and found level III easier to use, more convenient and most acceptable to repeat than Level I and II studies. Given autonomy is an important principle, patient preference of sleep diagnostic tests should be taken into consideration in sleep clinical services and research involving pregnant women.

Diagnosis and management of common sleep disorders during the perinatal period

The perinatal period is a critical phase in a woman's life characterized by significant physical, emotional, and societal changes. Sleep disorders such as insomnia, restless legs syndrome, obstructive sleep apnea, and poor sleep quality have been observed to increase in prevalence during the perinatal period. Given the harmful impact of sleep disturbances on the health of both mother and newborn, it is crucial to diagnose and treat them promptly. There is a paucity of literature on sleep problems during the perinatal period. This narrative review aimed to summarize the existing evidence and provide suggestions for promptly identifying and managing these disorders.

Validation of the Apnealink Air for diagnosis of obstructive sleep apnoea (OSA) in pregnant women in early-mid gestation

PURPOSE

The detection of obstructive sleep apnoea (OSA) in pregnant women in early-mid gestation is logistically difficult. Accurate alternates to polysomnography (PSG) in early pregnancy are not well identified. We compared the agreement between Apnealink Air (AL) and existing screening questionnaires to PSG in pregnant women ≤ 24-week gestation.

METHODS

Pregnant women (≤ 24-week gestation) underwent AL at home plus attended PSG in any order, completed within 7 days where practicable. AL was manually scored (AL(M)) and automatically scored (AL(A)). An apnoea-hypopnea index (AHI) ≥ 5 was considered diagnostic of OSA and an AHI ≥ 15 considered at least moderate OSA. Diagnostic analysis was undertaken (sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV)) by generating receiver operating characteristic (ROC) curves and an area under the curve (AUC) (95% CI). Bland-Altman plots were used to plot agreement. Screening questionnaires (Epworth sleepiness score (ESS), STOP-BANG, calculated pregnancy-specific screening tool) were compared to PSG.

RESULTS

A total of 49 participants successfully completed both tests at around 14-weeks gestation (IQR 12.9, 17.1). The time interval between AL and PSG was a median of 2 days (IQR 1, 5 (range 1-11)). A total of 14 (29%) participants had OSA. The median AHI of AL(A) (3.1(IQR 0.85,4.6)) and AL(M) (IQR2.4(0.65,4.8)) did not differ from PSG (1.7(IQR1.0,6.1)). AL(A) and AL(M) compared to PSG demonstrated diagnostic test accuracy (area under curve (ROC)) of 0.94(95% CI 0.87-1.0) and 0.92(95% CI 0.85-1.0) respectively. Apnealink Air outperformed screening questionnaires tested.

CONCLUSION

The findings suggest that Apnealink may provide a substitute to attended PSG identification of OSA in pregnant women in early-mid gestation using both manual and auto-scoring methods.

Sex Differences in Obstructive Sleep Apnea Including Pregnancy and Response to Treatment

This article highlights the sex differences in obstructive sleep apnea (OSA) and sheds light on the varying presentations, diagnostic challenges, as well as treatment responses observed in men and women. The disparities in prevalence, manifestations, and therapeutic outcomes underscore the need for a nuanced approach to OSA diagnosis and management that considers sex-specific factors. Furthermore, this article highlights the importance of recognizing and treating OSA during pregnancy, as it poses unique challenges and potential risks to both maternal and fetal health.

Maternal sleep disordered breathing and offspring growth outcome: A systematic review and meta-analysis

Sleep disordered breathing is extremely common in pregnancy and is a risk factor for maternal complications. Animal models demonstrate that intermittent hypoxia causes abnormal fetal growth. However, there are conflicting data on the association between maternal sleep disordered breathing and offspring growth in humans. We investigated this association by conducting a systematic review and meta-analysis. Sixty-three manuscripts, and total study population of 67, 671, 110 pregnant women were included. Thirty-one studies used subjective methods to define sleep disordered breathing, 24 applied objective methods and eight used international codes. Using a random effects model, habitual snoring, defined by subjective methods, and obstructive sleep apnea, diagnosed by objective methods, were associated with an increased risk for large for gestational age (OR 1.46; 95%CI 1.02-2.09 and OR 2.19; 95%CI 1.63-2.95, respectively), while obstructive sleep apnea, identified by international codes, was associated with an increased risk for small for gestational age newborns (OR 1.28; 95%CI 1.02-1.60). Our results support that maternal sleep disordered breathing is associated with offspring growth, with differences related to the type of disorder and diagnostic methods used. Future studies should investigate underlying mechanisms and whether treatment of sleep disordered breathing ameliorates the neonatal growth.

Sleep disorders during pregnancy: an underestimated risk factor for gestational diabetes mellitus

Sleep disorders are highly prevalent during pregnancy and significantly affect women's health and quality of life. Gestational diabetes mellitus (GDM) is one of the most common metabolic complications during pregnancy and constitutes a significant risk factor for both mother and fetus in the short and the long term. While the association between sleep disorders and type 2 diabetes mellitus (T2DM) is indisputable, it is not clear whether there is a link between sleep disorders and GDM. The aim of this article was to investigate the association between sleep disorders and GDM and whether the treatment of sleep disorders may prevent GDM development. Insomnia, obstructive sleep apnea (OSA), restless legs syndrome (RLS), and narcolepsy were the most common sleep disorders identified during pregnancy and were related to poor sleep quality and short or prolonged sleep duration. They were all associated with an increased risk of GDM. The ideal sleep duration for pregnant women was determined at 8-9 h daily. In conclusion, sleep disorders constitute a risk factor for GDM. It is imperative that prospective studies be conducted to evaluate the effect of the early management of sleep disorders on GDM manifestation and control. Healthcare providers should highlight the importance of sufficient sleep to reinforce pregnancy outcomes.

Home monitoring for clinically suspected obstructive sleep apnea in pregnancy

STUDY OBJECTIVES

To determine if a home sleep apnea test (HSAT) using a type III portable monitor (PM), Nox-T3 (Nox Medical, Inc., Reykjavik, Iceland), detects obstructive sleep apnea in pregnant women.

METHODS

Ninety-two pregnant women (34.5 ± 4.3 years; gestational age 25.4 ± 8.9 weeks; body mass index 29.9 ± 4.7 kg/m2) with suspected obstructive sleep apnea underwent HSAT with the Nox-T3 PM followed by overnight polysomnography (PSG) and PM recording simultaneously in the laboratory within 1 week. PMs were scored automatically and manually using a 3% criteria and compared with PSGs scored by following guidelines.

RESULTS

Apnea-hypopnea indexes were 8.56 ± 10.42, 8.19 ± 13.79, and 8.71 ± 14.19 events/h on HSAT, in-laboratory PM recording, and PSG (P = .955), respectively. Bland-Altman analysis of the apnea-hypopnea index on PSG vs HSAT showed a mean difference (95% confidence interval) of -0.15 (-1.83, 1.53); limits of agreement (± 2 SD) were -16.26 to 16.56 events/h. Based on a threshold apnea-hypopnea index ≥ 5 events/h, HSAT had 91% sensitivity, 85% specificity, 84% positive-predictive value, and 92% negative-predictive value compared with PSG. When comparing the simultaneous recordings, closer agreement was observed. Automated vs manual analysis of PM showed no significant difference.

CONCLUSIONS

A type III PM had an acceptable failure rate and high diagnostic performance operating as a reasonable alternative for in-laboratory PSG in pregnant women.

CITATION

Wang J, Zhang C, Xu L, et al. Home monitoring for clinically suspected obstructive sleep apnea in pregnancy. J Clin Sleep Med. 2023;19(11):1951-1960.

Society of Anesthesia and Sleep Medicine and the Society for Obstetric Anesthesia and Perinatology Consensus Guideline on the Screening, Diagnosis, and Treatment of Obstructive Sleep Apnea in Pregnancy

The Society of Anesthesia and Sleep Medicine and the Society for Obstetric Anesthesia and Perinatology tasked an expert group to review existing evidence and to generate recommendations on the screening, diagnosis, and treatment of patients with obstructive sleep apnea during pregnancy. These recommendations are based on a systematic review of the available scientific evidence and expert opinion when scientific evidence is lacking. This guideline may not be appropriate for all clinical situations and patients, and physicians must decide whether these recommendations are appropriate for their patients on an individual basis. We recognize that not all pregnant people may identify as women. However, data on non-cisgendered pregnant patients are lacking, and many published studies use gender-binary terms; therefore, depending on the study referenced, we may refer to pregnant individuals as women. This guideline may inform the creation of clinical protocols by individual institutions that consider the unique considerations of their patient populations and the available resources.

Sleep quality in men with androgenetic alopecia

PURPOSE

Sleep disturbances affect human health and contribute to several comorbidities. In men, androgenetic alopecia (AGA) is a common, non-scarring form of hair loss that affects a patient's self-esteem. There are limited data regarding the association between poor sleep quality and male AGA. We aimed to compare the prevalence of sleep abnormalities between male patients with AGA and controls to identify an association between the two conditions.

METHODS

A case-control study on patients with AGA and age-matched controls was conducted. Participants completed a standardized questionnaire that contained self-evaluated sleep measures, including Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, and STOP-BANG questionnaire. Patients with AGA were classified into mild, moderate, and severe subgroups according to the Hamilton-Norwood classification for stratified analyses. Data between groups and among subgroups were compared.

RESULTS

Of 446 male participants, 223 (50%) were in the AGA group, and the remainder (50%) were in the control group. Multivariable logistic regression analysis revealed that hypertension (odds ratio [OR] = 1.90, 95% confidence interval [CI] = 1.16-3.11, p = 0.011) and STOP-BANG score ≥ 5 (OR = 2.05, 95%CI = 1.15-3.66, p = 0.015) were associated with AGA. For subgroup analyses, ordinal logistic regression model showed a significant association between severe AGA and three sleep profiles, namely total sleep time ≤ 6 h (OR = 2.16, 95%CI = 1.02-4.57, p = 0.044), PSQI > 5 (OR = 3.72, 95%CI = 1.42-9.72, p = 0.008), and STOP-BANG score ≥ 5 (OR = 3.01, 95%CI = 1.11-8.13, p = 0.030).

CONCLUSION

Our findings revealed an association between sleep disturbances and AGA, which may help guide appropriate management in these patients.

Development and psychometric properties of the sleep problems and coping with sleep problem scales for pregnant women

AIMS

The aim of this study is to develop a sleep problems scale and a coping with sleep problems scale for pregnant women and assess their reliability and validity.

DESIGN

An empirical research quantitative design.

REVIEW METHODS

Self-reported instruments were developed through (1) item generation, (2) preliminary item evaluation and (3) scale refining and evaluation. Item pools were created via literature review, opinions of experts and women with experience in pregnancy sleep. Content, construct and criterion validities were tested. Reliability was assessed using Cronbach's alpha, split-half reliability and corrected item-total correlation.

DATA SOURCES

Data were collected between January 23 and July 22, 2020, at a hospital's obstetrics polyclinic. In the pilot and main study, 30 and 368 pregnant women (gestational age: 8-42 weeks) were included, respectively.

RESULTS

The content validity index was >0.9 for each scale. Factor analysis showed 24 and 18 items in the two scales, both with four subdimensions. The corrected item-total correlations were acceptable, and Cronbach's alpha coefficient was 0.883 and 0.799, respectively.

CONCLUSION

Both scales developed in this study are valid and reliable for the Turkish society. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE/GLOBAL CLINICAL COMMUNITY: This study's findings may prevent the lack of validated screening instruments to identify pregnancy-specific sleep features.

IMPACT

We developed two scales to assess sleep problems in pregnant women. These were valid and reliable, can be routinely used by health professionals and may guide nurses and midwives in assessing and managing sleep problems during pregnancy.

REPORTING METHOD

The study conforms to the COSMIN checklist.

PATIENT OR PUBLIC CONTRIBUTION

Data were collected during face-to-face surveys. Ten women contributed to the item pool generation, 30 pregnant women participated in the pilot study, and 368 antenatal service users participated in the main study.

Obstructive Sleep Apnea Among Gravidas With Chronic Hypertension Compared to Matched Controls: A Prospective Cohort Study

BACKGROUND

Previous studies of obstructive sleep apnea (OSA) risk in gravidas with chronic hypertension (cHTN) did not control for obesity as a risk factor for OSA. We therefore performed this study to evaluate whether OSA is more prevalent among gravidas with cHTN compared to normotensive gravidas matched for body mass index (BMI) and gestational age (primary outcome). We also assessed whether OSA is more severe when comorbid with cHTN in pregnancy (secondary outcome).

METHODS

This was a single-center, prospective cohort study. Adult gravidas at 10-20 weeks of gestation, with and without cHTN, were enrolled and BMI matched. All subjects answered OSA screening questionnaires and underwent a home sleep test when they were between 10 and 20 weeks of gestation. Pregnancy outcomes were followed for all subjects. We performed univariable and multivariable logistic regression to model the relationship between cHTN status and OSA.

RESULTS

A total of 100 pregnant subjects (50 with cHTN and 50 normotensive) completed a home sleep test of 2 hours or more. There were no differences in demographic variables between the 2 groups, except that gravidas with cHTN were significantly older than normotensive subjects (mean ± standard deviation [SD] 34 ± 4 vs 30 ± 6 years; P < .001). OSA was more prevalent (64% vs 38%; P = .009; odds ratio [95% confidence interval (CI)] 2.90 [1.30-6.65]; P = .01) and more severe in gravidas with cHTN (moderate or severe OSA 59% vs 21%; P = .009). After controlling for age, we found no overall association between cHTN on OSA risk (adjusted odds ratio [95% CI] 2.22 [0.92-5.40]; P = .076). However, among gravidas older than 25 years of age, cHTN was associated with higher odds of OSA (adjusted odds ratio [95% CI], 2.64 [1.06-6.71], P = .038).

CONCLUSIONS

cHTN and age are important risk factors for OSA in gravidas. Gravidas with cHTN should be screened for OSA in early pregnancy. Future studies may validate screening tools that include cHTN and age, and investigate the role of OSA therapy in blood pressure control.

Clinical application of a previously validated pregnancy-specific screening tool for sleep apnea in a cohort with a high prevalence of obesity

Objective

The purpose of this project was to determine the positive predictive value of existing obstructive sleep apnea (OSA) screening tools in clinical use, in a real-world clinical population of gravidae, and to explore the development of a new questionnaire for screening for OSA during pregnancy.

Methods

Pregnant people were administered sleep screening questionnaires as part of routine clinical care. These included Facco's four variable OSA screening tool, the STOP-BANG, and the Epworth Sleepiness Scale. Those who screened positive were referred for diagnostic sleep testing, typically with a type III home monitoring device. Here we analyzed the screening responses used by those who completed diagnostic testing to determine the positive predictive value of the existing tools.

Results

159 pregnant people completed diagnostic OSA testing and were included in this analysis. The positive predictive value of Facco's four variable sleep screening tool was 74.3%, STOP-BANG was 75.3%, and the Epworth Sleepiness Scale was 69.8%. Our sample size was insufficient to create a new screening tool.

Conclusions

Here we calculated the positive predictive value of Facco's 4 variable screening tool for screening for OSA in pregnancy in a real-world pregnant population. While we were not able to generate a new screening tool for screening for OSA during pregnancy, both STOP-BANG and Facco's four variable tool had positive predictive values over 70% in our population which was characterized by high BMI and advanced maternal age. Increased clinical use of the pregnancy-specific tool may be warranted.

Delivery outcomes as a result of snoring as determined by standard sleep surveys

Background

Sleep-disordered breathing (SDB), is an umbrella term that encompasses obstructive sleep apnea (OSA), central sleep apnea (CSA) and hypoventilation. is common but studies in the pregnant population are limited. Data suggests relationships between OSA and preeclampsia, but the relationship between snoring and pregnancy outcomes is unknown.

Methods

A prospective study of 2224 singleton pregnancies was undertaken. Women were questioned using the Berlin Questionnaire (BQ- 2 or more categories where the score is positive.) and the Epworth Sleepiness Scale (ESS >10/24), the results compared with pregnancy outcomes with regard to hypertension in pregnancy.

Results

Women having symptoms raising the possibility of OSA defined by the BQ with a score >7 was 45.5%, and using ESS with a score >10, was 36%. The birth and neonatal outcomes for self-reported snoring and increased daytime sleepiness showed increased adverse outcomes notably increased caesarean section rates and low APGAR scores but not birth before 37 weeks of gestation.

Conclusion

Using questionnaires designed for the general population, the prevalence of possible undiagnosed OSA is high in the pregnant population. The increased adverse delivery and neonatal outcomes for self-reported snoring and increased daytime sleepiness with these tools indicated the need for further investigation of the links between snoring SDB and pregnancy outcomes.

Fetal heart rate events during sleep, and the impact of sleep disordered breathing, in pregnancies complicated by preterm fetal growth restriction: An exploratory observational case-control study

OBJECTIVES

To evaluate fetal heart rate (FHR) patterns during sleep in pregnancies complicated by preterm fetal growth restriction (FGR). To determine whether co-existing sleep-disordered breathing (SDB) impacts on acute FHR events or perinatal outcome.

DESIGN

Observational case control study.

SETTING AND POPULATION

Women with preterm FGR and gestation-matched well grown controls (estimated fetal weight above the 10th percentile with normal Doppler studies); tertiary maternity hospital, Australia.

METHODS

A polysomnogram, a test used to measure sleep patterns and diagnose sleep disorders, and concurrent cardiotocography (CTG), were analysed for respiratory events and FHR changes.

MAIN OUTCOME MEASURES

Frequency of FHR events overnight in FGR cases versus controls and in those with or without SDB.

RESULTS

Twenty-nine patients with preterm FGR and 29 controls (median estimated fetal weight 1st versus 60th percentile, P < 0.001) underwent polysomnography with concurrent CTG at a mean gestation of 30.2 weeks. The median number of FHR events per night was higher among FGR cases than among controls (3.0 events, interquartile range [IQR] 1.0-4.0, versus 1.0 [IQR 0-1.0]; P < 0.001). Women with pregnancies complicated by preterm FGR were more likely than controls to be nulliparous, receive antihypertensive medications, be supine at sleep onset, and to sleep supine (32.9% of total sleep time versus 18.3%, P = 0.03). SDB was common in both FGR and control pregnancies (48% versus 38%, respectively, P = 0.55) but was generally mild and not associated with an increase in overnight FHR events or adverse perinatal outcome.

CONCLUSIONS

Acute FHR events overnight are more common in pregnancies complicated by preterm FGR than in pregnancies with normal fetal growth. Mild SDB was common in late pregnancy and well tolerated, even by fetuses with preterm FGR.

Obstructive sleep apnea in pregnant women

The prevalence of OSA in the low-risk obstetric population is thought to be low; best estimates have been extrapolated from the one available large prospective study and likely range between 3–8%.1 OSA prevalence in high-risk pregnant women such as those with obesity and chronic hypertension is significantly higher as extrapolated from several smaller prospective studies which have reported a prevalence as high as 37% in obese women.2 –6 Despite the high prevalence of OSA in high-risk pregnant women, it remains underdiagnosed due to several factors.

An emerging body of literature suggests that OSA may also have serious implications for the health of mothers and fetuses during and beyond pregnancy, but there is still no data to determine if OSA treatment mitigates these adverse outcomes. In this review, we will examine this body of literature from the perspective of the anesthesiologist: the association between pregnancy and the development or worsening of OSA; OSA as it relates to adverse maternal and fetal outcomes; antepartum and screening considerations for OSA in pregnant women; and recommendations regarding the peripartum management of OSA.

Sleep Disturbance in Pregnancy

Sleep is vital to life, even when women enter into pregnancy state. Good sleep is important for a healthy pregnancy. Sleep disturbances are common during pregnancy and can be due to the change of pregnancy itself or the results of sleep disorders. There is growing evidence linking sleep disturbances with adverse maternal and fetal outcomes. Differentiation of sleep disorders in order to provide appropriate treatment as well as promoting good sleep for pregnant women is important. A multidisciplinary team to provide sleep care during antenatal period may be needed.

Prediction Models of Obstructive Sleep Apnea in Pregnancy: A Systematic Review and Meta-Analysis of Model Performance

BACKGROUND

Gestational obstructive sleep apnea (OSA) is associated with adverse maternal and fetal outcomes. Timely diagnosis and treatment are crucial to improve pregnancy outcomes. Conventional OSA screening questionnaires are less accurate, and various prediction models have been studied specifically during pregnancy.

METHODS

A systematic review and meta-analysis were performed for multivariable prediction models of both development and validation involving diagnosis of OSA during pregnancy.

RESULTS

Of 1262 articles, only 6 studies (3713 participants) met the inclusion criteria and were included for review. All studies showed high risk of bias for the construct of models. The pooled C-statistics (95%CI) for development prediction models was 0.817 (0.783, 0850), I² = 97.81 and 0.855 (0.822, 0.887), I² = 98.06 for the first and second-third trimesters, respectively. Only multivariable apnea prediction (MVAP), and Facco models were externally validated with pooled C-statistics (95%CI) of 0.743 (0.688, 0.798), I² = 95.84, and 0.791 (0.767, 0.815), I² = 77.34, respectively. The most common predictors in the models were body mass index, age, and snoring, none included hypersomnolence.

CONCLUSIONS

Prediction models for gestational OSA showed good performance during early and late trimesters. A high level of heterogeneity and few external validations were found indicating limitation for generalizability and the need for further studies.

Parallel Assessment Challenges in Nutritional and Sleep Epidemiology

Sleep has been consistently linked to health outcomes in clinical studies, but only in recent years has sleep become a focus in epidemiologic studies and public health. In particular, the sizable prevalence of insufficient sleep in the population warrants well-designed epidemiologic studies to examine its impact on public health. As a developing field, sleep epidemiology encounters methodological challenges similar to those faced by nutritional epidemiology research. In this article, we describe a few central challenges related to assessment of sleep duration in population-based studies in comparison with measurement challenges in nutritional epidemiology. In addition, we highlight 3 strategies applied in nutritional epidemiology to address measurement challenges and suggest ways these strategies could be implemented in large-scale sleep investigations.

The Berlin Questionnaire in pregnancy predominantly identifies obesity

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is common in pregnant women and is a risk factor for poor perinatal outcomes. The Berlin Questionnaire (BQ) is a validated OSA screening tool that is often used in pregnancy. However, its poor performance in this population is likely attributed to the scoring paradigm that primarily identifies obesity. Moreover, the associations between the BQ and pregnancy outcomes are often those same outcomes that are obesity-related. Therefore, this study examined associations between each of the three BQ domains, independently and jointly, in relation to gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP).

METHODS

Pregnant third-trimester women were recruited from a tertiary medical center and completed the BQ, which includes three independent domains: snoring; sleepiness; and obesity/high blood pressure. Medical records were accessed for diagnoses of GDM and HDP.

RESULTS

Of the 1,588 pregnant women, 44% had a positive BQ score. Women with a positive score for domains of snoring exclusively, sleepiness exclusively, or their combination did not have an increased risk for GDM or HDP. However, women without snoring or sleepiness, but with a positive score on the BMI/BP domain had increased odds of GDM (OR 2.0, 95%CI 1.3-3.3) and HDP (OR 2.9, 95%CI 1.6-5.5). Further, any positive score in domain combinations that included BMI/BP had increased odds of GDM and HDP compared with negative scores in all domains. In addition, presence of obesity without hypertension, snoring, or sleepiness, the odds of GDM and HDP were similarly increased.

CONCLUSIONS

The poor performance of the BQ in screening for OSA risk, may be attributed to its predominant reliance on identification of obesity.

Snoring and depression symptoms in pregnant women

OBJECTIVE

Pregnant patients are vulnerable to both depression and sleep-disordered breathing, and both convey risks for maternal and fetal outcomes. Previous research has indicated that sleep-disordered breathing is associated with depression, but further information related to the risk of depression based on timing of onset of snoring is needed.

DESIGN

When presenting to clinic for their initial prenatal visit, pregnant patients completed a packet of questionnaires, which included measures related to depression (Edinburgh Postnatal Depression Scale) and snoring. Habitual snoring was defined as snoring 3 or more nights per week.

RESULTS

In total, 1367 women were included and 34.1% reported habitual snoring, either chronic (24.4%) or pregnancy-onset (9.8%), with increased frequency of pregnancy-onset habitual snoring in later stages of pregnancy. Unadjusted analyses suggested increased odds of depressive symptoms in chronic and pregnancy-onset habitual snoring groups relative to nonsnorers (odds ratio [OR]: 2.01, 95% confidence interval [CI]: 1.39, 2.92, P < .01; OR: 2.50, 95% CI: 1.54, 4.07, P < .01, respectively). These findings were maintained after adjusting for maternal age, marital status, gestational age, and parity (chronic habitual snoring OR: 1.69, 95% CI: 1.14, 2.53, P < .01; pregnancy-onset habitual snoring OR: 2.79, 95% CI: 1.35, 5.78, P < .01).

CONCLUSIONS

Maternal snoring may be a risk factor for prenatal depressive symptoms. Pregnancy-onset habitual snoring confers additional risk for depression compared to not snoring during pregnancy.

Obstructive sleep apnea screening in young people: Psychometric validation of a shortened version of the STOP-BANG questionnaire using categorical data methods

BACKGROUND:

The STOP-BANG is an easily administrable questionnaire for the screening of obstructive sleep apnea in adults, which may be adapted for use by young people. Here, we assessed the psychometric properties of the STOP-BN, a shortened version of the STOP-BANG questionnaire, using categorical data methods.

METHODS:

Four hundred and three young people (age 20.71 ± 1.93 years) were selected by random sampling to participate in this cross-sectional study. Participants completed the STOP-BN, a tool for recording social and demographic characteristics, and the Epworth Sleepiness Scale (ESS), a measure of daytime sleepiness. The obtained data were analyzed using categorical data methods.

RESULTS:

A two-factor model was identified for the STOP-BN, using the Kaiser's criteria (eigenvalue >1) and the screen test. However, the parallel analysis based on minimum rank, and the cumulative variance criteria (>40%) identified an one-factor model. Factor loadings ranged from 0.364 to 0.745. The identified two-factor model showed acceptable fit as the reported goodness of fit index and weighted root mean square residual were in the ideal range, and the comparative fit index was close to the ideal range. Greatest lower bound to reliability for two factors of the STOP-BN was 0.67 and 0.67, indicating an acceptable internal consistency. A weak to a nonsignificant correlation between the ESS and the STOP-BN score was demonstrated, favoring STOP-BN's divergent validity.

CONCLUSION:

Categorical methods support the psychometric validity of the STOP-BN in the study population.

Prevalence of symptoms and risk of obstructive sleep apnea in Saudi pregnant women

BACKGROUND:

This case-control study aimed to assess the prevalence of symptoms and risk of obstructive sleep apnea (OSA) among Saudi pregnant women.

METHODS:

The study included consecutive Saudi pregnant women attending the antenatal service between July 2015 and December 2016. Pregnant women were compared with an age-matched group of nonpregnant women. OSA symptoms and risk were assessed using a validated Arabic version of the Berlin questionnaire (BQ).

RESULTS:

The study included 742 pregnant women and 742 age-matched nonpregnant women. At the time of the survey, 8.2% were in the first trimester; 33.4% in the second trimester; and 58.4%in third trimester. Snoring was reported by 14% of pregnant women, and 5% reported breathing pauses during sleep. Based on the BQ stratification for risk of OSA, 19.3% of pregnant women and 16.6% of the control group were at high risk for OSA. A comparison between the high OSA-risk and low OSA-risk pregnant women revealed that the pregnant women in high risk group were older (30.9 ± 5.9 years vs. 29 ± 5.4 years, P = 0.001), had a higher body mass index (BMI) (34.3 ± 5.2 kg/m² vs. 28.7 ± 5.8 kg/m², P < 0.001), and higher parity (1.9 ± 2 vs. 1.5 ± 1.7, P = 0.020). A multivariate logistic regression analysis revealed the following independent variables, BMI (odds ratio [OR] 1.173 [95% confidence interval [CI] 1.129–1.219],P < 0.001), pregnancy-induced hypertension (OR 7.85 [95% CI 1.691–36.447], P = 0.013), and the presence of restless legs syndrome (OR 2.209 [95% CI 1.332–3.279],P < 0.001).

CONCLUSIONS:

OSA symptoms and risk were relatively common among Saudi pregnant women. Increasing the awareness among physicians about this association is essential to improve early detection of the disorder.

Nocturnal oxygen desaturation in the late third trimester of uncomplicated pregnancy for prediction of late-onset gestational hypertension

AIM

This study aimed to determine whether 1-night screening of oxygen desaturation in women with uncomplicated pregnancy about 1 month before the due date is useful to predict late-onset gestational hypertension (GH) after 37 weeks of gestation.

METHODS

We recruited 102 women with uncomplicated pregnancy between 34 and 36 weeks of gestation. These women then completed the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Berlin Questionnaire for obstructive sleep apnea, and recorded their oxygen saturation (SpO₂ ) and physical acceleration profiles during nocturnal sleep for 1 night at home using a portable pulse oximeter and actigraph, respectively. Thereafter, their blood pressure was monitored weekly until delivery.

RESULTS

Pulse oximetry data between 34 and 36 weeks of gestation revealed that three women had an oxygen desaturation index (ODI) ≥5.0 and seven had a minimum SpO₂ < 90%. During follow-up until delivery, two women with an ODI ≥5.0 and a minimum SaO₂ <90% developed GH at 37 weeks of gestation. Among clinical measures at recruitment, body mass index (BMI) and pulse oximetry measures appeared available for the prediction of GH. The positive predictive values (95% confidence intervals) of the criteria using these measures were 0.67 (0.26-0.67) for ODI ≥5.0, 0.29 (0.10-0.35) for minimum SpO₂ <90%, and 0.07 (0.02-0.07) for BMI ≥25.0.

CONCLUSION

For the prediction of late-onset GH after 37 weeks of gestation, pulse oximetry measures about 1 month before the due date are particularly useful because of their high positive predictive values.

The effect of sleep impairment on gestational diabetes mellitus: a systematic review and meta-analysis of cohort studies

OBJECTIVE

This systematic review and meta-analysis evaluated the influence of sleep duration or impairment (poor sleep quality, snoring, and obstructive sleep apnea [OSA]) on gestational diabetes mellitus (GDM) risk.

METHODS

PubMed, Embase, EBSCO, and WOS databases were searched up to March 4th, 2019. Cohort studies were included and relative risk (RR) with 95% confidence interval (CI) were used as the measure of effects. Heterogeneity was assessed by the Chi-squared and I² tests. Subgroup analyses, sensitivity analysis, and dose-response analysis were performed. The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

A total of 16 studies with 2,551,017 pregnant women and 142,103 GDM cases were included in this study. Both short and long sleep duration were associated with increased risk of GDM. There was a U-shaped relationship between sleep duration and GDM risk (P_{-nonlinearity} < 0.001), and pregnant women with 8 h of sleep presented lower GDM risk. Poor sleep quality, snoring and OSA also increased the subsequent risk of GDM.

CONCLUSIONS

Pregnant women should be made aware of the benefits of proper sleep, and those with poor sleep quality, snoring, and OSA should be screened for GDM.

Feto-placental Dopplers are not altered in women with obstructive sleep apnoea symptoms

BACKGROUND

Snoring, gasping or choking during sleep are common symptoms of sleep-disordered breathing and are associated with multiple adverse maternal and obstetric outcomes. The mechanisms responsible remain unknown; however, placental dysfunction is suspected.

AIMS

The aim of this study was to investigate feto-placental and fetal cardiac function in women with pregnancies complicated by obstructive sleep apnoea symptoms.

MATERIALS AND METHODS

This was a prospective observational cohort study at a large tertiary obstetric hospital in Australia. Women were asked to complete a questionnaire relating to the presence and severity of obstructive sleep apnoea symptoms. They also underwent an ultrasound scan where Doppler indices of various feto-placental vessels and fetal cardiac function were measured. Regional cerebral perfusion was also assessed.

RESULTS

A total of 255 women were included in the final analysis. Of these, 36.1% (92/255) of women reported no obstructive sleep apnoea symptoms; 63.9% (163/255) reported they experienced some form of obstructive sleep apnoea symptoms that included any frequency of snoring or choking/gasping, while 42.0% (107/255) complained of severe obstructive sleep apnoea symptoms (snoring ≥ 3 times a week or choking/gasping). There were no significant differences in feto-placental Dopplers or fetal cardiac function parameters in women with obstructive sleep apnoea symptoms. There were also no differences in regional cerebral blood flow between groups, or any correlation with severity of symptoms.

CONCLUSIONS

Our data challenge the current perspective that adverse perinatal outcomes in women with obstructive sleep apnoea symptoms are related primarily to placental dysfunction and fetal compromise.

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

BACKGROUND AND OBJECTIVES

Sleep-disordered breathing (SDB) affects up to one third of women during late pregnancy and is associated with adverse pregnancy outcomes, including hypertension, diabetes, impaired fetal growth, and preterm birth. However, it is unclear if SDB is associated with late stillbirth (≥28 weeks' gestation). The aim of this study was to investigate the relationship between self-reported symptoms of SDB and late stillbirth.

METHODS

Data were obtained from five case-control studies (cases 851, controls 2257) from New Zealand (2 studies), Australia, the United Kingdom, and an international study. This was a secondary analysis of an individual participant data meta-analysis that investigated maternal going-to-sleep position and late stillbirth, with a one-stage approach stratified by study and site. Inclusion criteria: singleton, non-anomalous pregnancy, ≥28 weeks' gestation. Sleep data ('any' snoring, habitual snoring ≥3 nights per week, the Berlin Questionnaire [BQ], sleep quality, sleep duration, restless sleep, daytime sleepiness, and daytime naps) were collected by self-report for the month before stillbirth. Multivariable analysis adjusted for known major risk factors for stillbirth, including maternal age, body mass index (BMI kg/m2), ethnicity, parity, education, marital status, pre-existing hypertension and diabetes, smoking, recreational drug use, baby birthweight centile, fetal movement, supine going-to-sleep position, getting up to use the toilet, measures of SDB and maternal sleep patterns significant in univariable analysis (habitual snoring, the BQ, sleep duration, restless sleep, and daytime naps). Registration number: PROSPERO, CRD42017047703.

RESULTS

In the last month, a positive BQ (adjusted odds ratio [aOR] 1.44, 95% confidence interval [CI] 1.02-2.04), sleep duration >9 hours (aOR 1.82, 95% CI 1.14-2.90), daily daytime naps (aOR 1.52, 95% CI 1.02-2.28) and restless sleep greater than average (aOR 0.62, 95% CI 0.44-0.88) were independently related to the odds of late stillbirth. 'Any' snoring, habitual snoring, sleep quality, daytime sleepiness, and a positive BQ excluding the BMI criterion, were not associated.

CONCLUSION

A positive BQ, long sleep duration >9 hours, and daily daytime naps last month were associated with increased odds of late stillbirth, while sleep that is more restless than average was associated with reduced odds. Pregnant women may be reassured that the commonly reported restless sleep of late pregnancy may be physiological and associated with a reduced risk of late stillbirth.

Maternal sleep disordered breathing assessed by Epworth Sleepiness Scale and abnormal feto-placental Dopplers

Objective: Excessive daytime sleepiness is a frequently described phenomenon in pregnant women. The Epworth Sleepiness Scale (ESS) is a self reported standardized method of assessing sleep propensity and has been used extensively within pregnant populations. An elevated score is associated with sleep disordered breathing, as well as adverse obstetric and neonatal outcomes which may be indicative of a degree of placental dysfunction. Thus the aim of this study was to prospectively assess women using the Epworth questionnaire in conjunction with an ultrasound in both the second and third trimesters to determine if there was a difference in ESS scores across gestation and if a mid or late gestation assessment was correlated with Doppler ultrasound measures of fetal well-being.Materials and methods: Participants were prospectively recruited from a tertiary obstetric hospital and completed both an Epworth questionnaire and ultrasound examination in the second and third trimesters.Results: A total of 302 women took part in this cohort study. There was a statistically significant (p = .02) increase in ESS score across gestation. There was however no correlation identified in either the second or third trimester between ESS score and umbilical artery pulsatility index, middle cerebral artery pulsatility index, cerebroplacental ratio, umbilical venous flow, uterine artery pulsatility index or estimated fetal weight. A higher birth weight is associated with a higher ESS score in the second trimester but not in the third trimester (p = .03).Conclusions: Maternal sleep disordered breathing assessed by the ESS score is only correlated with increased birth weight but not with fetal Doppler parameters in low risk pregnancies.

Sleep and sleep disorders in pregnancy

Pregnancy is associated with a number of physiologic changes in the body including hormonal, anatomical, and mechanical. These changes alter many physiologic functions including sleep. The literature suggests that a number of women develop changes in duration, pattern, and quality of sleep during pregnancy. In addition, these changes also pave the way for expression of sleep disorders (e.g., insomnia, obstructive sleep apnea, and restless legs syndrome). Change in sleep and appearance of sleep disorders not only influence pregnant women, but also have negative influences on the fetus and outcomes of pregnancy. However, optimal management of these disorders may reverse adverse consequences. In this chapter, risk factors, clinical presentation, and management of insomnia, obstructive sleep apnea, and restless legs syndrome during pregnancy are discussed in view of the available literature.

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.

The STOP-Bang Questionnaire as a Screening Tool for Obstructive Sleep Apnea in Pregnancy

STUDY OBJECTIVES

We examined the validity of the STOP-Bang questionnaire and a modified STOP-Bang questionnaire to screen for obstructive sleep apnea (OSA) in women with obesity during the second trimester of pregnancy.

METHODS

Ninety-nine pregnant women age 18 years or older with body mass index ≥ 40 kg/m² completed the STOP-Bang questionnaire during their second trimester. The number of oxygen desaturation events (≥ 4% from baseline) was measured using overnight pulse oximetry, with OSA defined as ≥ 5 events/h. A Modified STOP-Bang score was derived by replacing the "Tired" item with Epworth Sleepiness Scale score ≥ 10. Seven candidate models were compared using information theoretic criteria: STOP-Bang, Modified STOP-Bang, and individual STOP-Bang items (Snore, Tired, Observed to stop breathing, high blood Pressure and Neck circumference). We used penalized logistic regression and negative binomial regression to derive predicted probabilities of having OSA and the predicted total event counts.

RESULTS

The predicted probability of meeting oximetry criteria for OSA increased with higher STOP-Bang scores, from < 10% for a score < 3 to 68% with a score of 6. The total number of disordered breathing events was 1.26 (95% confidence interval 1.06 to 1.50) times greater for a 1-unit increase in STOP-Bang. Of the candidate models, the best relative fit was the Snore item followed by STOP-Bang score (essentially equivalent). The predicted probability of having OSA was 5.0% for no snoring and 26.4% for snoring.

CONCLUSIONS

STOP-Bang has been shown to be a useful screening tool for OSA in pregnant women with obesity; however, the snoring question alone might be a simpler, effective predictor.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: STOPBANG As A Screening Tool for Obstructive Sleep Apnoea in Pregnancy; URL: https://clinicaltrials.gov/ct2/show/NCT02542488; Identifier: NCT02542488.

Pregnant pause: should we screen for sleep disordered breathing in pregnancy?

Physiological and hormonal changes in pregnancy can contribute towards sleep disordered breathing in pregnant women (SDBP). When present, SDBP increases the risk of several adverse maternal and fetal outcomes independent of factors such as age, weight and pre-existing maternal comorbidities. SDBP is underdiagnosed and may be hard to recognise because the presentation can be difficult to differentiate from normal pregnancy and the severity may change over the course of gestation. Timely intervention seems likely to help reduce adverse outcomes, but the relative benefits of intervention are still unclear. The definition of what constitutes a sleep-related breathing “disorder” in pregnancy may be different to the general population and so traditional thresholds for intervention may not be relevant in pregnancy. Any modifications to the disease definition in this group, or implementation of more intensive screening, may result in overdiagnosis. Further research is needed to help clinicians evaluate the balance of benefits and harms in this process. Until this is clearer there is a strong imperative for shared decision making in screening and treatment decisions, and screening programmes should be monitored to assess whether improved outcomes can be achieved at the healthcare system level.

Untreated sleep disordered breathing in pregnancy poses risks to maternal and fetal wellbeing, but thresholds for and effectiveness of intervention are unclear. Clinicians should use shared decision making for screening and treatment decisions.http://ow.ly/N0oN30noWnx

Obstructive sleep apnoea in multiple pregnancy

Obstructive sleep apnoea (OSA) during pregnancy has been associated with gestational diabetes mellitus, hypertension and low birth weight. Multiple pregnancy is associated with similar adverse perinatal outcomes. Multiple pregnancy rates have risen with increased access to assisted conception; simultaneously, advancing maternal age and weight are also driving a rise in the incidence of OSA in pregnancy. The intersection of OSA and multiple pregnancy would be presumed to have significant maternal and fetal morbidity; however, specific data are sparse. We review the current state of knowledge on OSA in multiple pregnancy.

Sleep-Disordered Breathing in Pregnancy

Sleep-disordered breathing (SDB) in pregnancy can present as snoring and/or obstructive sleep apnea (OSA), and the prevalence is increasing due to the increase in maternal obesity. Pregnant women often present with fatigue and daytime sleepiness rather than the classic symptoms. Habitual snoring, older age, chronic hypertension, and high prepregnancy body mass index are reliable indicators of increased risk for SDB and should trigger further testing. The gold standard for diagnosis of OSA is an overnight laboratory polysomnography. Although there are no studies linking SDB to poor fetal outcomes, fetal well-being remains paramount throughout the course of pregnancy.

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.

A review of the associations between obstructive sleep apnea and hypertensive disorders of pregnancy and possible mechanisms of disease

Obesity is prevalent among pregnant women in the United States; 15-20% of obese pregnant women have obstructive sleep apnea. The prevalence of obstructive sleep apnea increases along with body mass index, age and in the presence of other co-morbidities. Untreated obstructive sleep apnea in women is associated with a range of cardiovascular, pulmonary and metabolic co-morbidities; recent studies suggest that women with obstructive sleep apnea in pregnancy may be at significantly greater risk of entering pregnancy with chronic hypertension and/or of developing hypertensive disorders of pregnancy: gestational hypertension; preeclampsia; or eclampsia. This has serious public health implications; hypertensive disorders of pregnancy are a major cause of maternal and neonatal morbidity and mortality and are associated with a greater lifetime risk for cardiovascular disease. The mechanisms that associated obstructive sleep apnea with hypertensive disorders of pregnancy have not been defined, but several pathways are scientifically plausible. In this review, we will present a comprehensive literature review of the following: the associations between obstructive sleep apnea and hypertensive disorders of pregnancy; the proposed mechanisms that may connect obstructive sleep apnea and hypertensive disorders of pregnancy; and the effectiveness of treatment at mitigating these adverse outcomes.

Predictors of sleep-disordered breathing in pregnancy

BACKGROUND

Sleep-disordered breathing (SDB) is common in pregnancy, but there are limited data on predictors.

OBJECTIVES

The objective of this study was to develop predictive models of sleep-disordered breathing during pregnancy.

STUDY DESIGN

Nulliparous women completed validated questionnaires to assess for symptoms related to snoring, fatigue, excessive daytime sleepiness, insomnia, and restless leg syndrome. The questionnaires included questions regarding the timing of sleep and sleep duration, work schedules (eg, shift work, night work), sleep positions, and previously diagnosed sleep disorders. Frequent snoring was defined as self-reported snoring ≥3 days per week. Participants underwent in-home portable sleep studies for sleep-disordered breathing assessment in early (6-15 weeks gestation) and mid pregnancy (22-31 weeks gestation). Sleep-disordered breathing was characterized by an apnea hypopnea index that included all apneas, plus hypopneas with ≥3% oxygen desaturation. For primary analyses, an apnea hypopnea index ≥5 events per hour was used to define sleep-disordered breathing. Odds ratios and 95% confidence intervals were calculated for predictor variables. Predictive ability of the logistic models was estimated with area under the receiver-operating-characteristic curves, along with sensitivities, specificities, and positive and negative predictive values and likelihood ratios.

RESULTS

Among 3705 women who were enrolled, data were available for 3264 and 2512 women in early and mid pregnancy, respectively. The corresponding prevalence of sleep-disordered breathing was 3.6% and 8.3%, respectively. At each time point in gestation, frequent snoring, chronic hypertension, greater maternal age, body mass index, neck circumference, and systolic blood pressure were associated most strongly with an increased risk of sleep-disordered breathing. Logistic regression models that included current age, body mass index, and frequent snoring predicted sleep-disordered breathing in early pregnancy, sleep-disordered breathing in mid pregnancy, and new onset sleep-disordered breathing in mid pregnancy with 10-fold cross-validated area under the receiver-operating-characteristic curves of 0.870, 0.838, and 0.809. We provide a supplement with expanded tables, integrated predictiveness, classification curves, and an predicted probability calculator.

CONCLUSION

Among nulliparous pregnant women, logistic regression models with just 3 variables (ie, age, body mass index, and frequent snoring) achieved good prediction of prevalent and incident sleep-disordered breathing. These results can help with screening for sleep-disordered breathing in the clinical setting and for future clinical treatment trials.