Pregnant women with gestational hypertension may have a high frequency of sleep disordered breathing

Association between sleep disturbances during pregnancy and adverse perinatal outcomes

OBJECTIVE

To describe the changes in sleep pattern throughout pregnancy and to evaluate the relationship between sleep and adverse perinatal outcomes.

METHODS

Pregnant women at Qianfoshan Hospital completed questionnaires regarding their sleep during each of the three trimesters. Additionally, a subset of participants engaged in objective sleep monitoring using actigraphy devices. In the perinatal period, the following data were collected: pregnancy complications; gestational age; mode of delivery; Apgar scores for the neonate; and birth weight.

RESULTS

The total night sleep time in the second trimester was about 15 minutes shorter than that in the first trimester (P=0.024), and about 31 minutes shorter in the third trimester than in the second trimester (P<0.001). The sleep efficiency in the second trimester was about 10.23% lower than in the first trimester (P<0.001), and the efficiency in the third trimester was about 5.16% lower than in the second trimester (P<0.001). The occurrence of pregnancy-induced hypertension (PIH) was associated with sleep duration (P=0.019), sleep efficiency (P<0.001) and PSQI scores (P<0.001) in the first trimester. Furthermore, the mode of delivery was also found to be associated with sleep duration (P=0.011), sleep efficiency (P<0.001) and PSQI scores (P<0.001) in the first trimester.

CONCLUSION

With the development of the pregnancy process, the sleep situation gets worse. Pregnant women's sleep situation in the first trimester of pregnancy is associated with the occurrence of PIH and delivery mode.

Obstructive Sleep Apnoea: A Shrouded High-Risk Association for Development of Hypertensive Disorders of Pregnancy

Background

This objective of this study was to diagnose Obstructive Sleep Apnoea (OSA) in pregnant women using Questionnaire-based methods and to determine any association of Sleep-Disordered Breathing (SDB) with Hypertensive Disorder of Pregnancy (HDP). Additionally, the study aimed to identify factors associated with OSA.

Methods

This case-control study was conducted in department of Obstetrics in tertiary care hospital in Delhi. We Identified SDB using Berlin Questionnaire and Modified Stop-Bang Questionnaire in 100 pregnant women with Hypertension and 100 normotensive controls. We compared the groups using appropriate statistical analysis.

Results

The mean age of women with HDP (25.46 ± 4.38) was found to be slightly higher than controls (24.13 ± 3.89) (p value-0.02). Sleep apnoea as depicted by the presence of either high-risk STOP Bang or Berlin score was seen more often in hypertensive women in 45% as compared to controls in 8% (p value < 0.001). Higher pre-pregnancy weight (58.58 ± 9.77 vs. 53.0 ± 6.59), higher BMI (24.03 ± 5.89 vs. 20.68 ± 1.49), higher mean neck circumference (14.97 vs. 14.27 inches) weight gain more than 11 kg during pregnancy (55.6% vs. 38.2%) were the high-risk factors more commonly associated with SDB as seen in women with OSA in hypertensive women. On logistic regression analysis, the presence of OSA was singularly responsible for development of Hypertension (Odds Ratio-13.014, 95% CI 5.237-32.337) (p value < 0.001).

Conclusion

Gestational hypertension appears to be strongly associated with the presence of obstructive sleep apnoea. The recognition and treatment of OSA during pregnancy may lead to improved outcomes.

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.

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.

Association between sleep quality, hypertensive disorders of pregnancy, and sleep-disordered breathing in pregnant women with and without obesity: An observational cross-sectional study

AIM

To elucidate whether pregnancy and obesity are associated with poor sleep quality, and to investigate if sleep quality is associated with hypertensive disorders of pregnancy in pregnant women with obesity.

METHODS

This observational cross-sectional study examined 15 obese pregnant women (body mass index ≥30 kg/m² ) (p-Ob group), 15 nonobese pregnant women (p-nOb group), and 30 nonobese nonpregnant women (n-Pr group), using home recording devices to monitor sleep-disordered breathing (SDB): respiratory disturbance index, oxygen saturation, and sleep stage and quality. These variables were compared among the groups. Moreover, obese women with and without hypertensive disorders of pregnancy were compared.

RESULTS

Significant differences in respiratory disturbance index (median: 10.3 [p-Ob], 7.1 [p-nOb], 3.5 [n-Pr]) and oxygen saturation (95.1%, 96.5%, and 96.6%) were observed among the groups. Seven participants in the p-Ob group experienced hypertensive disorders of pregnancy with SDB before or after sleep examination. Particularly, those who developed hypertensive disorders of pregnancy before sleep examination showed a lower delta power throughout the night than those without this condition.

CONCLUSION

Pregnant women had poor sleep quality; those with obesity had higher frequency of SDB with worsened respiratory conditions that might cause complications. Our findings suggest that the development of hypertensive disorders of pregnancy in some obese pregnant women might be associated with insufficient delta power. Focusing on delta power may reflect subtle changes in sleep quality that occur in pregnant women. Future longitudinal studies with larger sample sizes are required to confirm these findings and investigate causality.

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.

Influence of Obstructive Sleep Apnea on Systemic Inflammation in Pregnancy

Background: Obstructive sleep apnea (OSA) is prevalent in pregnancy and it is associated with adverse pregnancy-related outcomes such as gestational diabetes, pre-eclampsia, and low birth weight. Maternal systemic inflammation is proposed to be one of the main intermediate mechanisms. However, the effects of OSA on systemic inflammation are unknown in normal pregnancy.

Methods: Women in the 3rd trimester underwent hospital polysomnography to evaluate whether OSA increases systemic inflammation in normal pregnancy and its potential association with adverse fetal outcomes. OSA was defined as an apnea–hypopnea index (AHI) of ≥ 5 h⁻¹. Plasma cytokines levels (TNF-α, IL-1β, IL-6, IL-8, and IL-10) were determined by multiple immunoassays.

Results: We included 11 patients with OSA and 22 women with AHI < 5 h⁻¹, who were homogeneous in age, and body mass index (BMI). Women with OSA had significant higher levels of TNF-α, IL-1β, IL-8, and IL-10. We found significant correlations between AHI during REM and TNF-α (r = 0.40), IL-1β (r = 0.36), IL-6 (r = 0.52), IL-8 (r = 0.43), between obstructive apnea index and TNF-α (r = 0.46) and between AHI and IL-1β (r = 0.43). We also found that CT90% was related to IL-8 (r = 0.37). There were no significant differences in neonatal characteristics; however, we found inverse correlations between TNF-α and IL-8 with birth weight (both r = −0.48), while IL-8 showed a significant inverse relationship with neonatal gestational age (r = −0.48).

Conclusions: OSA in our normal pregnancy population was associated with higher systemic inflammation, which was related to obstructive events, especially during REM sleep. Moreover, systemic inflammation was inversely correlated with neonatal birth weight and age.

Fetal Heart Rate Decelerations in Women with Sleep-Disordered Breathing

Emerging literature has shown that women with sleep-disordered breathing (SDB) have increased risk for gestational hypertension/preeclampsia and gestational diabetes. Case reports suggest an association between maternal apnea and fetal heart rate deceleration but data are lacking on how maternal sleep impacts fetal health. Since decelerations may be associated with adverse outcomes, we sought to determine whether fetal heart rate decelerations were associated with SDB. A cohort study of third trimester pregnant women with a singleton fetus was conducted. Participants underwent a home sleep test with continuous portable electronic fetal monitoring. SDB was defined as a respiratory disturbance index (RDI)≥10 events/hour. The temporality between a respiratory event and fetal heart rate decelerations was determined to be present if a deceleration occurred < 30 s after a respiratory event. Forty women were included with mean (±SD) age, BMI, and gestational age of 32.0±5.5 years, 37.1±8.0 kg/m², and 34.6±2.4 weeks respectively. Overall, n=23 (57.5%) women had SDB. Thirty-seven late decelerations were observed in 18 women; of these, 84% were temporally associated with a respiratory event. Nine of the 18 women (50%) had SDB. Ten prolonged decelerations were observed in 6 women of which nine (90%) were temporally associated with a respiratory event. Five of the six women (83%) had an RDI≥10. These initial data suggest that, in this population, the majority of both late and prolonged fetal heart rate decelerations occur with a maternal respiratory event. Since respiratory events are characteristic of maternal SDB, this raises the possibility that SDB may influence fetal well-being.

Sleep-disordered breathing in pregnancy: a developmental origin of offspring obesity?

Sleep-disordered breathing (SDB) worsens over pregnancy, and obstructive sleep apnea is associated with serious maternal complications. Intrauterine exposures that provoke insulin resistance (IR), inflammation, or oxidative stress may have long-term offspring health consequences. In obesity, worsening maternal SDB appears to be an exposure that increases the risk for both small- or large-for-gestational-age (SGA, LGA, respectively), suggesting distinct outcomes linked to a common maternal phenotype. The aim of this paper is to systematically review and link data from both mechanistic rodent models and descriptive human studies to characterize the impact of maternal SDB on fetal development. A systematic review of the literature was conducted using PubMed, Embase, and CINAHL (01/2000-09/2019). Data from rodent (9 studies) and human models (48 studies, 5 meta-analyses) were included and reviewed using PRISMA guidelines. Evidence from rodent models suggests that intermittent maternal hypoxia results in mixed changes in birth weight (BW) followed by accelerated postnatal growth, while maternal sleep fragmentation results in normal BW followed by later metabolic derangement. Human studies support that maternal SDB is associated with both SGA and LGA, both of which may predispose offspring to later obesity. Evidence also suggests a link between SDB, inflammation, and oxidative stress that may impact maternal metabolism and/or placental function. SDB is common in pregnancy and affects fetal growth and development. Given that SDB has significant potential to adversely influence the intrauterine metabolic environment, larger, prospective studies in humans are urgently needed to fully elucidate the effects of this exposure on offspring metabolic risk.

Sleep disturbances during pregnancy and adverse maternal and fetal outcomes: A systematic review and meta-analysis

Sleep disturbances are highly prevalent in pregnancy and are frequently overlooked as a potential cause of significant morbidity. The association between sleep disturbances and pregnancy outcomes remains largely controversial and needs to be clarified to guide management. To evaluate the association between sleep disturbances and maternal complications and adverse fetal outcomes, we performed a systematic search of PubMed, Embase and Web of Science for English-language articles published from inception to March 6, 2020, including observational studies of pregnant women with and without sleep disturbances assessing the risk of obstetric complications in the antenatal, intrapartum or postnatal period, and neonatal complications. Data extraction was completed independently by two reviewers. We utilized the Newcastle-Ottawa Scales to assess the methodological quality of included studies and random-effect models to pool the associations. A total of 120 studies with 58,123,250 pregnant women were included. Sleep disturbances were assessed, including poor sleep quality, extreme sleep duration, insomnia symptoms, restless legs syndrome, subjective sleep-disordered breathing and diagnosed obstructive sleep apnea. Significant associations were found between sleep disturbances in pregnancy and a variety of maternal complications and adverse fetal outcomes. Overall sleep disturbances were significantly associated with pre-eclampsia (odds ratio = 2.80, 95% confidence interval: 2.38-3.30), gestational hypertension (1.74, 1.54-1.97), gestational diabetes mellitus (1.59, 1.45-1.76), cesarean section (1.47, 1.31-1.64), preterm birth (1.38, 1.26-1.51), large for gestational age (1.40, 1.11-1.77), and stillbirth (1.25, 1.08-1.45), but not small for gestational age (1.03, 0.92-1.16), or low birth weight (1.27, 0.98-1.64). Sleep disturbances were related to higher morbidities in pregnant women who are 30 y or older and overweight before pregnancy. The findings indicate that sleep disturbances, which are easily ignored and treatable for both pregnant women and clinical services, deserve more attention from health care providers during prenatal counseling and health care services.

Sleep-Disordered Breathing and Pregnancy-Related Cardiovascular Disease

Sleep-disordered breathing (SDB) is a serious medical condition characterized by intermittent episodes of airflow limitation, intermittent hypoxia, and sleep disturbance triggering a pattern of autonomic dysfunction associated with hypertension, diabetes, and other adverse health conditions. SDB incidence is two to three times higher during pregnancy and is associated with an increased risk of cardiometabolic complications, including pre-eclampsia and gestational diabetes. Treatments to protect breathing during sleep are available, pointing to SDB as a potential therapeutic target to reduce maternal cardiometabolic morbidity. However, in clinical practice, the majority of SDB cases in pregnancy are undiagnosed, indicating a need to improve screening for SDB risk factors and referral for diagnostic testing. Furthermore, definitive clinical trials are needed to determine the extent to which SDB intervention reduces the risk of adverse cardiovascular and neonatal outcomes in pregnancy. This review article discusses an accumulation of research pointing to SDB as a prevalent risk factor for gestational cardiometabolic disease, as well as a potential therapeutic target to reduce cardiometabolic morbidity.

Sleep-disordered breathing does not impact maternal outcomes in women with hypertensive disorders of pregnancy

Objective

Sleep-disordered breathing (SDB) is characterised by intermittent hypoxemia, sympathetic activation and widespread endothelial dysfunction, sharing pathophysiologic features with the hypertensive disorders of pregnancy. We sought to determine whether coexisting SDB would adversely impact the outcomes of women with gestational hypertension (GH) and preeclampsia (PE), and healthy matched controls.

Study design

Women diagnosed with GH or PE along with BMI- and gestation-matched normotensive controls underwent polysomnography in late pregnancy to establish the presence or absence of SDB (RDI ≥ 5). Clinical outcomes of hypertensive disease severity were compared between groups, and venous blood samples were taken in the third trimester and at delivery to examine for any impact of SDB on the anti-angiogenic markers of PE.

Results

Data was available for 17 women with PE, 24 women with GH and 44 controls. SDB was diagnosed in 41% of the PE group, 63% of the GH group and 39% of the control group. Women with PE and co-existing SDB did not have worse outcomes in terms of gestation at diagnosis of PE (SDB = 29.1 (25.9, 32.1) weeks vs. no SDB = 32.0 (29.0, 33.9), p = n.s.) and days between diagnosis of PE and delivery (SDB = 20.0 (4.0, 35.0) days vs. no SDB = 10.5 (9.0, 14.0), p = n.s.). There were also no differences in severity of hypertension, antihypertensive treatment and biochemical, haematological and anti-angiogenic markers of PE between SDB and no SDB groups. Similar results were observed among women with GH. Healthy control women with SDB were no more likely to develop a hypertensive disorder of pregnancy in the later stages of pregnancy (SDB = 5.9% vs. no SDB = 7.4%, p = n.s.). Increasing the threshold for diagnosis of SDB to RDI ≥ 15 did not unmask a worse prognosis.

Conclusion

The presence of SDB during pregnancy did not worsen the disease course of GH or PE, and was not associated with high blood pressure or anti-angiogenic markers of hypertensive disease amongst healthy pregnant women. Given the numerous reports of the relationship between SDB and diagnosis of hypertensive disorders of pregnancy, it appears more work is required to distinguish causal, versus confounding, pathways.

Sleep Disordered Breathing, a Novel, Modifiable Risk Factor for Hypertensive Disorders of Pregnancy

PURPOSE OF REVIEW

Pathophysiology of hypertensive disorders of pregnancy (HDP), especially preeclampsia, has not been fully elucidated. Most trials aimed at the prevention of preeclampsia have failed to show significant benefit and investigation of novel, modifiable risk factors is sorely needed. Sleep disordered breathing (SDB), a group of disorders for which treatments are available, meets these criteria. SDB impacts about a third of all pregnancies and is associated with hypertension in the general non-pregnant population.

RECENT FINDINGS

Recent studies have shown a high prevalence of SDB, especially in complicated pregnancies. Several studies have shown that pregnant women with SDB have a higher risk for developing HDP, and these two disorders are associated with similar maternal long-term cardiovascular outcomes. Based on limited animal models of gestational intermittent hypoxia and human studies, SDB and HDP share similar risk factors and some pathophysiological mechanisms. However, there is paucity of studies addressing causality of this association and identifying therapeutic targets for intervention. Maternal SDB represents a novel and modifiable risk factor of HDP. Further studies are needed in order to establish the exact mechanisms underlying this association and to identify specific areas for clinical interventions.

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.

Obstructive Sleep Apnea in Pregnant Women: A Review of Pregnancy Outcomes and an Approach to Management

Among obese pregnant women, 15%-20% have obstructive sleep apnea (OSA) and this prevalence increases along with body mass index and in the presence of other comorbidities. Prepregnancy obesity and pregnancy-related weight gain are certainly risk factors for sleep-disordered breathing in pregnancy, but certain physiologic changes of pregnancy may also increase a woman's risk of developing or worsening OSA. While it has been shown that untreated OSA in postmenopausal women is associated with a range of cardiovascular, pulmonary, and metabolic comorbidities, a body of literature is emerging that suggests OSA may also have serious implications for the health of mothers and fetuses during and after pregnancy. In this review, we discuss the following: pregnancy as a vulnerable period for the development or worsening of OSA; the associations between OSA and maternal and fetal outcomes; the current screening modalities for OSA in pregnancy; and current recommendations regarding peripartum management of OSA.

Pathophysiological changes associated with sleep disordered breathing and supine sleep position in pregnancy

Sleep is a complex and active physiological process that if disrupted, can result in adverse outcomes both within and outside of pregnancy. Sleep disordered breathing (SDB) occurs in 10-32% of pregnancies. Substantial physiological changes occur during pregnancy that impact on maternal sleep, which typically deteriorates with advancing gestation. Pregnancy challenges maternal homeostatic regulation of many systems which effect maternal sleep, including the respiratory, cardiovascular, endocrine, and immune systems. SDB can result from varying degrees of airway compromise and potentially cause systemic hypoxia. The hypoxia may be acute, intermittent or chronic in nature with complications dependant on the duration and the gestation at which the insult occurs. It is unlikely that this effect is mediated by a singular mechanistic pathway but results from a complex cascade of events across multiple maternal organ systems. Regardless of the etiology, both SDB and supine sleep position are associated with a variety of obstetric and perinatal complications including, pre-eclampsia/eclampsia, gestational diabetes mellitus, cardiomyopathy, heart failure, fetal growth restriction, poor neonatal condition at birth, stillbirth and neuro-psychiatric problems in offspring. Both maternal sleep position and sleep disordered breathing are potentially modifiable or treatable factors that if addressed have the potential to improve maternal and fetal outcomes. This narrative review summarizes the maternal and placental pathophysiological aberrations associated with sleep disordered breathing and supine sleep position in 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.

Maternal Weight, Snoring, and Hypertension: Potential Pathways of Associations

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are linked to excessive maternal weight and frequent snoring. However, pathways between maternal excessive weight, pregnancy-onset snoring, and HDP are only partially estimated. We examined and quantified the total and direct associations between excessive maternal weight and incident HDP and their indirect pathway through pregnancy-onset snoring.

METHODS

Third trimester pregnant women enrolled from prenatal clinics of a large tertiary medical center. Sleep data were collected through a questionnaire. Demographic and pregnancy information and first trimester maternal weight were abstracted from medical charts. After exclusion of women with prepregnancy hypertension and/or chronic snoring, causal mediation analysis was used to estimate the total and direct association between maternal weight and incident HDP and their indirect association through pregnancy-onset snoring. The proportion of the mediated association through pregnancy-onset snoring from the total association of maternal weight and HDP was also quantified.

RESULTS

After excluding those with chronic hypertension and/or snoring, the final sample included 1,333 pregnant women. In adjusted analysis, excessive maternal weight was directly associated with incident HDP; odds ratio (OR) = 1.87 (95% confidence interval (CI) 1.30, 2.70). Pregnancy-onset snoring significantly mediated the association between maternal weight and incident HDP; OR = 1.08 (95% CI 1.01, 1.17). The mediated pathway accounted for 15% of the total association between maternal weight and incident HDP.

CONCLUSIONS

Pregnancy-onset snoring mediates the association between maternal weight and incident HDP in women without prepregnancy snoring or hypertension. These findings demonstrate the relative contributions of excessive maternal weight and pregnancy-onset snoring to incident HDP.

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.

Sleep-disordered breathing in hypertensive disorders of pregnancy: a BMI-matched study

Sleep-disordered breathing is more common in hypertensive disorders during pregnancy; however, most studies have not adequately accounted for the potential confounding impact of obesity. This study evaluated the frequency of sleep-disordered breathing in women with gestational hypertension and pre-eclampsia compared with body mass index- and gestation-matched normotensive pregnant women. Women diagnosed with gestational hypertension or pre-eclampsia underwent polysomnography shortly after diagnosis. Normotensive controls body mass index-matched within ±4 kg m^-2 underwent polysomnography within ±4 weeks of gestational age of their matched case. The mean body mass index and gestational age at polysomnography were successfully matched for 40 women with gestational hypertension/pre-eclampsia and 40 controls. The frequency of sleep-disordered breathing in the cases was 52.5% compared with 37.5% in the control group (P = 0.18), and the respiratory disturbance index overall did not differ (P = 0.20). However, more severe sleep-disordered breathing was more than twice as common in women with gestational hypertension or pre-eclampsia (35% versus 15%, P = 0.039). While more than half of women with a hypertensive disorder of pregnancy meet the clinical criteria for sleep-disordered breathing, it is also very common in normotensive women of similar body mass index. This underscores the importance of adjusting for obesity when exploring the relationship between sleep-disordered breathing and hypertension in pregnancy. More severe degrees of sleep-disordered breathing are significantly associated with gestational hypertension and pre-eclampsia, and sleep-disordered breathing may plausibly play a role in the pathophysiology of pregnancy hypertension in these women. This suggests that more severe sleep-disordered breathing is a potential therapeutic target for reducing the prevalence or severity of hypertensive disorders in pregnancy.

Síndrome de apnea-hipopnea obstructiva del sueño (SAHOS) y embarazo

El embarazo es una condición temporal de la vida en la que ocurren importantes cambios en la fisiología de la mujer, los cuales se resuelven, en gran medida, después del parto. Hay cambios físicos, hormonales y psicológicos, con un aumento progresivo de peso. Estos factores pueden predisponer a un trastorno respiratorio del sueño o a exacerbar alguno ya existente. La literatura científica sugiere una mayor prevalencia de ronquido en las mujeres embarazadas. Las bases de datos demuestran que en menos del 1% de los embarazos aparece el código del diagnóstico de apnea de sueño. Se ha relacionado la presencia tanto de ronquido como de apnea durante el embarazo con algunos desenlaces adversos que se tratan en este artículo, el cual busca sensibilizar a los médicos para que consideren este diagnóstico durante el embarazo.

The Role of Obstructive Sleep Apnea in Developing Gestational Hypertension and Preeclampsia

Gestational hypertension and preeclampsia are the most frequent medical complications in pregnancy and major causes of maternal and fetal morbidity and mortality. It is also known that these conditions are associated with a long term increased cardiovascular global risk for these young women. Obstructive sleep apnea (OSA) seems to be not only a frequent pathology associated with pregnancy but also an independent factor for developing gestational hypertension. It is well known the relationship between gestational hypertension, preeclampsia and intrauterine growth restriction of the foetus so the outcomes of this pathologies are important for both mother and child. Increasing awareness of OSA among pregnant women with gestational hypertension and preeclampsia is important given the potential benefits of the treatment with continuous positive airway pressure (CPAP) on these patients.

Hemodynamic Response to Upper Airway Obstruction in Hypertensive and Normotensive Pregnant Women

Background. Mild obstructive sleep apnea is common in pregnancy and may have an exacerbating role in gestational hypertension, although currently the interaction between these two diseases is uncertain. Methods. We analyzed 43 pregnant subjects, 28 with gestational hypertension (GH) and 15 with normal healthy pregnancy, by level I polysomnography. Additionally, diastolic and systolic blood pressure changes in response to obstructive respiratory events were measured by noninvasive beat-by-beat monitoring. We also assessed a subgroup (n = 27) of women with respiratory disturbance indexes <5, for blood pressure responses to very subtle obstructive respiratory disturbances (“airflow reductions”). Results. The mean ± standard deviation respiratory disturbance index of our 28 GH women and 15 healthy pregnant women was 10.1 ± 9.9 mmHg and 3.0 ± 3.8 mmHg, respectively. Systolic and diastolic pressure responses to these events were 30.1 ± 12.8 mmHg and 16.0 ± 6.1 mmHg for GH women and 29.1 ± 14.2 mmHg and 14.3 ± 7.7 mmHg for healthy women. For the 27 women in whom we assessed for airflow reduction events, the hemodynamic responses were 27.1 ± 12.3 mmHg systolic and 14.4 ± 6.7 mmHg diastolic. Interpretation. Upper airway obstructive events of any severity are associated with a substantial transient blood pressure response in both healthy pregnant and GH women. Whether or not these events have a clinically significant impact on women with GH remains uncertain.

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

This review aims to evaluate the performance of obstructive sleep apnea (OSA) screening questionnaires during pregnancy. A systematic review and meta-analysis was performed using MEDLINE Scopus, CINAHL, and the Cochrane library. A bivariate meta-analysis was applied for pooling of diagnostic parameters. Six of the total 4719 articles met the inclusion criteria. The Berlin questionnaire (BQ, N = 604) and Epworth sleepiness scale (ESS, N = 420) were the most frequently used screening tools during pregnancy. The pooled prevalence of OSA during pregnancy was 26.7% (95%CI: 16.9%, 34.4%, I² = 83.15%). BQ performance was poor to fair with pooled sensitivity and specificity of 0.66 (95%CI: 0.45, 0.83; I² = 78.65%) and 0.62 (95%CI: 0.48, 0.75; I² = 81.55%), respectively. BQ performance was heterogeneous depending on type of reference test and pregnancy. Sensitivity increased if diagnosis was based on polysomnography (0.90), and respiratory disturbance index (0.90). However, sensitivity decreased if screening was performed in early pregnancy (≤20 weeks gestation: 0.47), and high-risk pregnancy (0.44). Performance of ESS was poor with pooled sensitivity and specificity of 0.44 (95%CI: 0.33, 0.56; I² = 32.8%) and 0.62 (95%CI: 0.48, 0.75; I² = 81.55%), respectively. In conclusion, BQ and ESS showed poor performance during pregnancy, hence a new OSA screening questionnaire is needed. Registration: PROSPERO registration CRD42015025848.

Sleep-disordered breathing and future cardiovascular disease risk

Sleep-disordered breathing occurs in 0.6-15% of reproductive age women. This condition is associated with an increased lifetime risk of cardiovascular disease, cardiovascular mortality, and all-cause mortality. A substantial body of evidence demonstrated increased perinatal morbidity among pregnancies affected by SDB including gestational diabetes, gestational hypertension, and preeclampsia. These same conditions are predictive of later cardiovascular disease. Treatment of SDB has been demonstrated to decrease future cardiovascular events and mortality. Screening at-risk individuals in the perinatal period can identify women with SDB, who can benefit from treatment. Continuous positive airway pressure and lifestyle interventions can decrease subsequent adverse cardiovascular health outcomes.

Sleep-disordered breathing during pregnancy: future implications for cardiovascular health

IMPORTANCE

Cardiovascular disease (CVD) is a common condition in postreproductive females. Key risk factors for later-life CVD include gestational hypertension (GHTN) and preeclampsia (PE). Although several risk factors of hypertension in pregnancy are well recognized, a novel risk factor that has emerged recently is sleep-disordered breathing (SDB), a condition characterized by repeated closure of the upper airway during sleep with disrupted ventilation and sleep fragmentation. In the nonpregnant population, SDB is now known to play a causal role in future CVD.

OBJECTIVE

The aim of this study was to propose the hypothesis that occult SDB during pregnancy may play a role in long-term CVD in women who had hypertensive disorders of pregnancy.

EVIDENCE ACQUISITION

This study is a review and synthesis of empirical evidence that links SDB to GHTN/PE and GHTN/PE to future CVD.

RESULTS

An increasing body of evidence supports the relationship between SDB and hypertensive disorders of pregnancy via mechanisms of inflammation, oxidative stress, and endothelial dysfunction. It is well established that hypertensive disorders of pregnancy are associated with long-term risk for CVD via similar mechanisms. However, no studies have addressed the potential role of SDB in long-term outcomes of women with GHTN/PE during pregnancy.

CONCLUSIONS

Given the suggested mechanisms that explain these associations, it is plausible that SDB during pregnancy may increase long-term cardiovascular morbidity and mortality.

RELEVANCE

Pregnancy may offer a window of opportunity for identification and treatment of SDB, which could provide substantial health benefit for many years to come.

Gender differences in sleep disordered breathing: implications for therapy

There are gender differences in the upper airway function and respiratory stability in obstructive sleep apnea (OSA). Hormones are implicated in some gender-related differences, and these differences between men and women appear to mitigate as age increases. In addition, changes in the airway and lung function during pregnancy can contribute to snoring and OSA that might have an adverse effect on the mother and fetus. The limited data available suggest that although the prevalence and severity of OSA may be lower in women, the consequences of the disease are similar, if not worse. Women with OSA may have greater risk for hypertension and endothelial dysfunction, be more likely to develop comorbid conditions such as anxiety and depression and have increased mortality. Therefore, treatment options specifically targeting female presentations and pathophysiology of sleep-disordered breathing (SDB) are expected to result in improved outcomes in women.

Hypertension, snoring, and obstructive sleep apnoea during pregnancy: a cohort study

OBJECTIVE

To assess the frequency of obstructive sleep apnoea among women with and without hypertensive disorders of pregnancy.

DESIGN

Cohort study.

SETTING

Obstetric clinics at an academic medical centre.

POPULATION

Pregnant women with hypertensive disorders (chronic hypertension, gestational hypertension, or pre-eclampsia) and women who were normotensive.

METHODS

Women completed a questionnaire about habitual snoring and underwent overnight ambulatory polysomnography.

MAIN OUTCOME MEASURES

The presence and severity of obstructive sleep apnoea.

RESULTS

Obstructive sleep apnoea was found among 21 of 51 women with hypertensive disorders (41%), but in only three of 16 women who were normotensive (19%, chi-square test, P=0.005). [Author correction added on 16 June 2014, after first online publication: Results mentioned in the abstract were amended.] Non-snoring women with hypertensive disorders typically had mild obstructive sleep apnoea, but >25% of snoring women with hypertensive disorders had moderate to severe obstructive sleep apnoea. Among women with hypertensive disorders, the mean apnoea/hypopnoea index was substantially higher in snorers than in non-snorers (19.9±34.1 versus 3.4±3.1, P=0.013), and the oxyhaemoglobin saturation nadir was significantly lower (86.4±6.6 versus 90.2±3.5, P=0.021). Among women with hypertensive disorders, after stratification by obesity, the pooled relative risk for obstructive sleep apnoea in snoring women with hypertension compared with non-snoring women with hypertension was 2.0 (95% CI 1.4-2.8).

CONCLUSIONS

Pregnant women with hypertension are at high risk for unrecognised obstructive sleep apnoea. Although longitudinal and intervention studies are urgently needed, given the known relationship between obstructive sleep apnoea and hypertension in the general population, it would seem pertinent that hypertensive pregnant women who snore should be tested for obstructive sleep apnoea, a condition believed to cause or promote hypertension.

Obstructive sleep apnea and the risk of perinatal outcomes: a meta-analysis of cohort studies

Inconsistent information exists in the relationship between obstructive sleep apnea (OSA) and perinatal outcomes. This study was intended to investigate whether OSA in pregnant women has a potential to elevate the incidence of the maternal and neonatal outcomes by performing a meta-analysis of all available cohort studies. Five cohort studies including 977 participants were eligible for inclusion. The association between OSA and the risk of perinatal outcomes was expressed as relative risks (RR), with 95% confidence interval (CI). Our results revealed that OSA group was associated with more frequent preeclampsia (RR 1.96; 95% CI 1.34 to 2.86), preterm birth (RR 1.90; 95%CI 1.24 to 2.91), cesarean delivery (RR 1.87; 95% CI 1.52 to 2.29) and neonatal intensive care unit (NICU) (RR 2.65; 95% CI 1.86 to 3.76). On analyzing data for the prevalence of gestational diabetes and small gestational age (SGA) < 10th percentile (RR 1.40; 95% CI 0.62 to 3.19, and RR 0.64; 95%CI 0.33 to1.24, respectively), there were no significant differences in both group. Findings from this meta-analysis indicate that OSA in pregnant women significantly increases the incidence of maternal and neonatal outcomes, which is associated with more frequent preeclampsia, preterm birth, cesarean delivery and NICU admission.

Antenatal depression: an artefact of sleep disturbance?

Research indicates that poor sleep quality is linked to and may precede depressive symptomatology in pregnancy, complicating screening for either condition. Pregnancy onset may also contribute to the development of sleep-disordered breathing (SDB). For the first time, the link between SDB and depression was examined in pregnancy. A total of 189 pregnant women completed the Edinburgh Postnatal Depression Scale (EPDS), Pittsburgh Sleep Quality Index (PSQI) for sleep quality and the Berlin Questionnaire for SDB. Women were also asked what they felt was the cause of their symptoms. PSQI-assessed poor sleep quality and self-perceived depression were strongly associated with EPDS scores of probable depression (X (2) 13.39; p < 0.001). Berlin-assessed risk of SDB was also associated with probable depression (X (2) 9.20 p < 0.01), though this was attenuated following multivariate analysis. There was a significant relationship between total PSQI score and the tendency for participants to attribute 'sleep-related causes' to their low mood (X (2) 20.78; p < 0.001). This study confirms the link between PSQI-assessed poor sleep quality and depressive symptoms in pregnancy, suggesting the two questionnaires assess the same or overlapping conditions. Although there was a relationship between probable depression and high risk SDB, the effect was attenuated after accounting for other depression risk factors, including body mass index (BMI).

Airflow limitations in pregnant women suspected of sleep-disordered breathing

BACKGROUND AND AIM

Pregnancy physiology may predispose women to the development of airflow limitations during sleep. The goal of this study was to evaluate whether pregnant women suspected of sleep-disordered breathing (SDB) are more likely to have airflow limitations compared to non-pregnant controls.

METHODS

We recruited pregnant women referred for polysomnography for a diagnosis of SDB. Non-pregnant female controls matched for age, body mass index (BMI), and apnoea-hypopnoea index (AHI) were identified from a database. We examined airflow tracings for changes in amplitude and shape. We classified airflow limitation by (a) amplitude criteria defined as decreased airflow of > or =10 s without desaturation or arousal (FL 10), or decreased airflow of any duration combined with either 1-2% desaturation or arousal, (FL 1-2%); and (b) shape criteria defined as the presence of flattening or oscillations of the inspiratory flow curve.

RESULTS

We identified 25 case-control pairs. Mean BMI was 44.0±6.9 in cases and 44.1±7.3 in controls. Using shape criteria, pregnant women had significantly more flow-limited breaths throughout total sleep time (32.4±35.8 vs. 9.4±17.9, p<0.0001) and in each stage of sleep (p<0.0001) than non-pregnant controls. In a subgroup analysis, pregnant women without a diagnosis of obstructive sleep apnoea (OSA) who had an AHI <5 had similar findings (p<0.0001). There was no difference in airflow limitation by amplitude criteria between pregnant women and controls (p=0.22).

CONCLUSIONS

Pregnant women suspected of OSA have more frequent shape-defined airflow limitations than non-pregnant controls, even when they do not meet polysomnographic OSA criteria.

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.

Fetal breathing movements and changes at birth

The fetus, which develops within a fluid-filled amniotic sac, relies on the placenta for respiratory gas exchange rather than the lungs. While not involved in fetal oxygenation, fetal breathing movements (FBM) nevertheless have an important role in lung growth and in development of respiratory muscles and neural regulation. FBM are regulated differently in many respects than postnatal respiration, which results from the unique intrauterine environment. Prominent distinctions of FBM include its episodic nature and apnea-sensitivity to hypoxia. The latter characteristic is the basis for using FBM in the assessment of fetuses at risk for hypoxic injury. At birth, the transition to continuous postnatal respiration involves a fall in temperature, gaseous distention of the lungs, activation of the Hering-Breuer reflexes, and functional connectivity of afferent O2 chemoreceptor activity with respiratory motoneurons and arousal centers. Importantly, exposure to drugs or adverse conditions in utero not only can change patterns of FBM but also can lead to epigenetic dysregulation in postnatal respiration. Such changes, can blunt respiratory and arousal defenses against hypoxic challenges in sleep. Thus, fetal hypoxia and/or drug exposure may in later life dispose sleeping infants, children, and adults to hypertension, diabetes mellitus, brain injury, and sudden death.

Maternal sleep-disordered breathing and adverse pregnancy outcomes: a systematic review and metaanalysis

OBJECTIVE

Symptoms of sleep-disordered breathing (SDB) are increased in pregnancy compared to the nongravid state. Maternal SDB may be associated with adverse pregnancy outcomes, but this is still under investigation. We performed a systematic literature review, and where feasible, a metaanalysis, to evaluate whether women with SDB in pregnancy have a higher risk of specific adverse pregnancy outcomes compared with women without SDB.

STUDY DESIGN

Original studies published until June 2012 evaluating the association between gestational hypertension/preeclampsia, gestational diabetes, low birthweight infants, and maternal SDB, defined either by symptoms or the reference standard polysomnography, were identified from PubMed, EMBASE, and Web of Science. Data were extracted on study design and outcome estimates. When appropriate, effect estimates from each study were pooled using a random-effects model.

RESULTS

Of the 4386 studies identified, 31 met the defined criteria. Twenty-one studies, all observational in design, reported dichotomous outcomes; 9 of these adjusted for potential confounders. Maternal SDB was significantly associated with gestational hypertension/preeclampsia (pooled adjusted odds ratio [aOR], 2.34; 95% confidence interval [CI], 1.60-3.09; 5 studies), and gestational diabetes (pooled aOR, 1.86; 95% CI, 1.30-2.42; 5 studies).

CONCLUSION

Based on published observational studies to date, maternal SDB is associated with an increased risk of gestational hypertension and gestational diabetes after adjusting for potential confounders. However, large-scale, prospective cohort, and interventional studies are needed to further elucidate the relationship between maternal SDB and adverse pregnancy outcomes.

Sleep and pregnancy-induced hypertension: a possible target for intervention?

Sleep disturbances in the general population are associated with elevated blood pressure. This may be due to several mechanisms, including sympathetic activation and hypothalamic-pituitary-adrenal (HPA) axis disturbance. Elevated blood pressure in pregnancy can have devastating effects on both maternal and fetal health and is associated with increased risk for preeclampsia and poor delivery outcomes. Preliminary evidence suggests that mechanisms linking sleep and blood pressure in the general population may also hold in the pregnant population. However, the effects of disturbed sleep on physiologic mechanisms that may directly influence blood pressure in pregnancy have not been well studied. The role that sleep disturbance plays in gestational blood pressure elevation and its subsequent consequences warrant further investigation. This review evaluates the current literature on sleep disturbance and elevated blood pressure in pregnancy and proposes possible treatment interventions.

Risk factors for sleep-disordered breathing in pregnancy

RATIONALE

Symptoms of sleep-disordered breathing (SDB) are common among pregnant women, and several studies link SDB symptoms with gestational hypertension and preeclampsia. However, few prospective studies objectively measuring SDB during pregnancy have been performed.

OBJECTIVES

We performed a prospective cohort study examining risk factors for third trimester SDB in pregnant women.

MEASUREMENTS AND METHODS

105 pregnant women from the Hospital of the University of Pennsylvania obstetrics practices completed first and third trimester overnight polysomnography studies. We examined whether the number of SDB events per hour of sleep increased during pregnancy. We performed unadjusted and multivariable logistic regression analyses to estimate the effects of usual and pregnancy-specific characteristics on development of third trimester obstructive sleep apnoea (OSA). In secondary analyses, we examined the relationship between objectively measured SDB, hypertensive disorders of pregnancy, and other adverse maternal-fetal outcomes.

MAIN RESULTS

Mean Apnoea-Hypopnoea Index increased from 2.07 (SD 3.01) events/h at baseline (first trimester) to 3.74 (SD 5.97) in the third trimester (p=0.009). 10.5% of women had OSA in the first trimester. By the third trimester, 26.7% of women had OSA. In multivariable analyses, first trimester body mass index (BMI) and maternal age were significantly associated with third trimester OSA.

CONCLUSIONS

Third trimester OSA is common. Risk factors for third trimester OSA among women without baseline SDB include higher baseline BMI and maternal age.