Serum Progesterone Levels in Pregnant Women with Obstructive Sleep Apnea: A Case Control Study

Sex-dependent effects of chronic intermittent hypoxia: implication for obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS).

METHODS

Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-6, IL-10, TNF-α), circulating steroid hormones, circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). Rats were implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype.

RESULTS

Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex.

CONCLUSIONS

Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.

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.

A Longitudinal Study of Respiratory Mechanics in Pregnant Women with Obesity and Overweight

PURPOSE

Respiratory mechanics and the role of sex hormones in pregnancy are not well elucidated. We examined longitudinal and positional changes in lung mechanics in pregnancy and investigated the role of sex hormones.

METHODS

A longitudinal study enrolled 135 women with obesity in early pregnancy. Fifty-nine percent of women identified as White; median body mass index at enrollment was 34.4 kg/m2. Women with respiratory disease were excluded. We obtained measurements of airway resistance and respiratory system reactance in various positions using impedance oscillometry and sex hormones in early and late pregnancy.

RESULTS

With pregnancy progression, there was a significant increase in resonant frequency (Fres) (p = 0.012), integrated area of low frequency reactance (AX) (p = 0.0012) and R5-R20Hz (p = 0.038) in the seated position, and a significant increase in R5Hz (p = 0.000), Fres (p = 0.001), AX (p < 0.001 = 0.000), and R5-R20Hz (p = 0.014) in the supine position. Compared to the seated position, the supine position was associated with a significant increase in R5Hz, R20Hz, X5Hz, Fres, and AX in early (p-values < 0.026) and late pregnancy (p-values ≤ 0.001). Changes in progesterone levels between early and late pregnancy predicted the change in R5, Fres, and AX (p-values ≤ 0.043).

CONCLUSION

Resistive and elastic loads increase with pregnancy progression and a change in body position from seated to supine increases resistive and elastic loads in both early and late pregnancies. The increase in airway resistance is primarily related to an increase in peripheral rather than central airways resistance. There was an association between the change in progesterone levels and airway resistance.

Poor sleep quality and associated factors among HIV-positive pregnant women in Northwest, Ethiopia: a facility-based, cross-sectional study

BACKGROUND

Poor sleep quality during pregnancy might have an impact on adverse birth outcomes like premature rupture of membrane, preterm birth, lifelong neurocognitive impairment, low birth weight, and increased the risk of neonatal morbidity and mortality. In Ethiopia, the magnitude of poor sleep quality among this group of people is extremely limited. So, this study aims to determine the magnitude of poor sleep quality and its associated factors among HIV-positive pregnant women attending public hospitals in Northwest Ethiopia.

METHODS

An institution-based cross-sectional study was done using a simple random sampling technique to recruit 411 HIV-positive pregnant women from January to March; 2021. Sleep quality over the last 1 month was measured using the Pittsburgh Sleep Quality Index (PSQI). General anxiety disorder (GAD-7), Sleep Hygiene Index (SHI), and List of Threatening of Experiences (LTE) instruments were used to identify factors associated with poor sleep quality. Bivariate and multivariable logistic regression with odds ratio and 95% CI were employed to identify determinant factors of poor sleep quality. Statistical significance association was declared at P-value < 0.05.

RESULTS

A total of 411 out of 423 HIV-positive pregnant women were interviewed, with a response rate of 97.1%. The overall magnitude of poor sleep quality among HIV-positive pregnant was found to be 39.4% with a 95% of confidence interval (CI) (34.3, 44.3). Stressful life events, [AOR = 3.10, 95% CI (1.60, 6.01)], having comorbid general anxiety symptoms [AOR = 2.46, 95% CI (1.58, 3.81)], unplanned pregnancy [AOR = 2.18, 95% CI (1.20, 3.96)], and poor sleep hygiene practice [AOR = 2.23, 95% CI (1.21, 4.10)] were significantly associated with poor quality of sleep.

CONCLUSION

The overall magnitude of poor sleep quality among HIV-positive pregnant women was high. Stressful life events, poor sleep hygiene, unplanned pregnancy, and comorbid general anxiety symptoms were the determinant factors of poor sleep quality that should be taken high consideration for early detection and appropriate intervention for poor sleep quality in HIV-positive pregnant women.

Sex Hormones, Sleep, and Memory: Interrelationships Across the Adult Female Lifespan

As the population of older adults grows, so will the prevalence of aging-related conditions, including memory impairments and sleep disturbances, both of which are more common among women. Compared to older men, older women are up to twice as likely to experience sleep disturbances and are at a higher risk of cognitive decline and Alzheimer's disease and related dementias (ADRD). These sex differences may be attributed in part to fluctuations in levels of female sex hormones (i.e., estrogen and progesterone) that occur across the adult female lifespan. Though women tend to experience the most significant sleep and memory problems during the peri-menopausal period, changes in memory and sleep have also been observed across the menstrual cycle and during pregnancy. Here, we review current knowledge on the interrelationships among female sex hormones, sleep, and memory across the female lifespan, propose possible mediating and moderating mechanisms linking these variables and describe implications for ADRD risk in later life.

Female sex hormones and symptoms of obstructive sleep apnea in European women of a population-based cohort

Background

The prevalence of obstructive sleep apnea is higher in women after menopause. This is suggested to be a result of an altered sex hormone balance but has so far not been confirmed in a population-based study.

Objective

To investigate whether serum concentration of estrogens and progesterone are associated with the prevalence of sleep apnea symptoms in middle-aged women of the general population.

Methods

We analyzed data from 774 women (40–67 years) from 15 study centers in seven countries participating in the second follow-up of the European Community Respiratory Health Survey (2010–2012). Multiple logistic regression models were fitted with self-reported symptoms of sleep apnea as outcomes and serum concentrations of various estrogens and progesterone as predictors. All analyses were adjusted for relevant covariates including age, BMI, education, study center, smoking habits, and reproductive age.

Results

Among all included women, a doubling of serum concentrations of estrone and progesterone was associated with 19% respectively 9% decreased odds of snoring. Among snorers, a doubling of the concentrations of 17β-estradiol, estrone and estrone 3-sulfate was associated with 18%, 23% and 17% decreased odds of breathing irregularly, and a doubling of the progesterone concentration was further associated with 12% decreased odds of waking up suddenly with a chocking sensation. Other evaluated associations were not statistically significant.

Conclusions

Middle-aged women with low serum estrogen and progesterone levels are more likely to snore and report symptoms of obstructive sleep apnea.

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.

The Effect of Gender and Sex Hormones on Cardiovascular Disease, Heart Failure, Diabetes, and Atrial Fibrillation in Sleep Apnea

Sleep apnea is a highly prevalent disorder with increasing impact on healthcare systems worldwide. Previous studies have been conducted primarily with male subjects, and prevalence and severity of sleep apnea in women are underestimated. Recent clinical and basic science evidence increasingly points to different mechanisms in men and women with sleep-disordered breathing (SDB). SDB is associated with a variety of comorbidities, including cardiovascular disease, heart failure, diabetes, and atrial fibrillation. In this review, we discuss sex-dependent mechanisms of SDB in select associated conditions to sharpen our clinical understanding of these sex-dependent inherent differences.

Maternal Sleep and Related Pregnancy Outcomes: A Multicenter Cross-Sectional Study in 11 Provinces of Iran

Objective: Sleep disturbance during pregnancy is one of the most common maternal complaints. Not only does it play a crucial role in a mother’s life, but also it comes with a multitude number of complications. This study aimed at assessing the association between sleep disturbance in pregnancy and maternal and child outcomes.

Materials and methods: This was a multicenter cross-sectional study, conducted on pregnant women across 11 provinces in Iran in 2018. Sleep disturbance as a composite variable was defined using the principal component analysis based on five questions. Abortion, anemia in the first and third trimester, gestational diabetes, gestational age, glucose tolerance test (GTT), fasting blood sugar (FBS), mode of delivery, low birth weight and stillbirth were defined as study outcomes.

Results: Totally, 3675 pregnant women enrolled in the study. Most of the participants (84.5%) reported that their sleep duration is less than 8 hours per day. The prevalence of sleep disturbance was 20.7% (95% CI: 19.1, 22.3). After adjusting for maternal age, education, job, place of residency and physical violence, sleep disturbance would increase the odds of abortion (p=0.009), anemia in both first (p=0.001) and third (p=0.003) trimester, gestational age (p=0.049), abnormal FBS (p=0.015) and cesarean section (p<0.001).

Conclusion: Regarding the effect of sleep quality on maternal outcomes, planning and implementing a suitable intervention in the context of primary health care is necessary. Increasing the awareness of mothers, health workers and medical personnel about the suitable quality and quantity of sleep during pregnancy is of great importance.

The effect of weight and body mass index on serum progesterone values and live birth rate in cryopreserved in vitro fertilization cycles

Objective

To determine if weight or body mass index (BMI) affects the serum progesterone level at the time of the pregnancy test in cryopreserved blastocyst transfer cycles and to determine if those serum progesterone levels affect live births.

Design

Retrospective cohort study.

Setting

US academic medical center.

Patient(s)

Six hundred thirty-three patients undergoing their first cryopreserved embryo transfer cycle.

Intervention(s)

None.

Main Outcome Measure(s)

The primary outcome was the serum progesterone level on the day of the pregnancy test by patient weight and BMI. Our secondary analysis assessed the serum progesterone effect on live birth rate (LBR) in a clinic where progesterone supplementation was increased if the progesterone level was <15 ng/mL on the day of the pregnancy test.

Results(s)

There was a strong negative correlation between serum progesterone level and both BMI and weight, with BMI accounting for 27% and weight accounting for 29% of the variance in progesterone level. Serum progesterone level on the day of the pregnancy test was <15 ng/mL in 3% of women weighing <68 kg compared with 29% of women weighing ≥90.7 kg. Among women weighing ≥90.7 kg, live birth occurred in 47% whose serum progesterone level was <15 ng/mL on the day of the pregnancy test compared with 49% in those with serum progesterone level of 15–19 ng/mL and 44% in those with serum progesterone level of ≥20 ng/mL.

Conclusion(s)

Body weight was a significant factor in serum progesterone level at the time of the pregnancy test, with nearly 30% of patients weighing ≥90.7 kg having serum progesterone level of <15 ng/mL, a value associated with lower LBRs in prior studies. However, we found no effect of low progesterone levels on LBR after cryopreserved embryo transfer cycles in a clinic where progesterone dosing was increased if serum progesterone levels were <15 ng/mL.

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.

Cardiovascular Disease in Women Across the Lifespan: The Importance of Sleep

Cardiovascular disease (CVD) and sleep disturbances are both common and associated with significant morbidity and mortality. Compared with men, women are more likely to report insufficient sleep. During the 2018 Research Conference on Sleep and the Health of Women sponsored by the National Heart, Lung, and Blood Institute, researchers in cardiology, integrative physiology and sleep medicine reviewed the current understanding of how sleep and sleep disturbances influence CVD in women across the lifespan. Women may be particularly vulnerable to the negative effects of sleep disturbances at important stages of their life, including during pregnancy and after menopause. The proposed pathways linking sleep disturbances and adverse cardiovascular outcomes in women are numerous and the complex interaction between them is not well understood. Future research focused on understanding the scope of sleep disorders in women, defining the underlying mechanisms, and testing interventions to improve sleep are critical for improving the cardiovascular health of all women.

Progesterone Actions During Central Nervous System Development

Although progesterone is a steroid hormone mainly associated with female reproductive functions, such as uterine receptivity and maintenance of pregnancy, accumulating data have shown its physiological actions to extend to several non-reproductive functions in the central nervous system (CNS) both in males and females. In fact, progesterone is de novo synthesized in specific brain regions by neurons and glial cells and is involved in the regulation of various molecular and cellular processes underlying myelination, neuroprotection, neuromodulation, learning and memory, and mood. Furthermore, progesterone has been reported to be implicated in critical developmental events, such as cell differentiation and neural circuits formation. This view is supported by the increase in progesterone synthesis observed during pregnancy in both the placenta and the fetal brain. In the present review, we will focus on progesterone actions during CNS development.

Increased risk of obstructive sleep apnoea in women with polycystic ovary syndrome: a population-based cohort study

OBJECTIVE

Obesity is very common in patients with obstructive sleep apnoea (OSA) and polycystic ovary syndrome (PCOS). Longitudinal studies assessing OSA risk in PCOS and examining the role of obesity are lacking. Our objective was to assess the risk of OSA in women with vs without PCOS and to examine the role of obesity in the observed findings.

DESIGN

Population-based retrospective cohort study utilizing The Health Improvement Network (THIN), UK.

METHODS

76 978 women with PCOS and 143 077 age-, BMI- and location-matched women without PCOS between January 2000 and May 2017 were identified. Hazard ratio (HR) for OSA among women with and without PCOS were calculated after controlling for confounding variables using multivariate Cox models.

RESULTS

Median patient age was 30 (IQR: 25-35) years; median follow-up was 3.5 (IQR: 1.4-7.1) years. We found 298 OSA cases in PCOS women vs 222 in controls, with incidence rates for OSA of 8.1 and 3.3 per 10 000 person years, respectively. Women with PCOS were at increased risk of developing OSA (adjusted HR = 2.26, 95% CI: 1.89-2.69, P < 0.001), with similar HRs for normal weight, overweight and obese PCOS women.

CONCLUSIONS

Women with PCOS are at increased risk of developing OSA compared to control women irrespective of obesity. Considering the significant metabolic morbidity associated with OSA, clinicians should have a low threshold to test for OSA in women with PCOS. Whether OSA treatment has an impact on PCOS symptoms and outcomes needs to be examined.

Sleep disorders in pregnancy

Anatomical, physiological, psychological and hormonal alterations affect sleep during pregnancy. Sleep appears tobe commonly impaired only after the first trimester. Albeit objective data regarding the reduction of sleep durationand efficiency are not univocal, poor sleep is reported by over half of pregnant women. The reasons underlyingthese complaints are multiple, including lower back pain, gastroesophageal reflux disorder (GERD), increasedmicturition and repositioning difficulties at night. Specific primary sleep disorders whose prevalence drasticallyincreases during pregnancy include obstructive sleep apnea (OSA) and restless legs syndrome (RLS), both relatedto gestational hypertension and gestational diabetes mellitus (GDM). Pre-eclampsia and labor complicationsleading to an increased number of cesarean sections and preterm births correlate with insomnia and OSA inparticular. Post-partum depression (PPD) and impairment of the mother-infant relationship may also be consideredas secondary effects deriving from poor sleep during pregnancy. Recognition and treatment of sleep disordersshould be encouraged in order to protect maternal and fetal health and prevent dire consequences at birth.

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.

Multiples of Median-Transformed, Normalized Reference Ranges of Steroid Profiling Data Independent of Age, Sex, and Units

BACKGROUND/AIMS

The high complexity of pediatric reference ranges across age, sex, and units impairs clinical application and comparability of steroid hormone data, e.g., in congenital adrenal hyperplasia (CAH). We developed a multiples-of-median (MoM) normalization tool to overcome this major drawback in pediatric endocrinology.

METHODS

Liquid chromatography tandem mass spectrometry data comprising 10 steroid hormones representing 905 controls (555 males, 350 females, 0 to > 16 years) from 2 previous datasets were MoM transformed across age and sex. Twenty-three genetically proven CAH patients were included (21-hydroxylase deficiency [21OHD], n = 19; 11β-hydroxylase deficiency [11OHD], n = 4). MoM cutoffs for single steroids predicting 21OHD and 11OHD were computed and validated through new, independent patients (21OHD, n = 8; adrenal cortical carcinoma, n = 6; obesity, n = 40).

RESULTS

21OHD and 11OHD patients showed disease-typical, easily recognizable MoM patterns independent of age, sex, and concentration units. Two single-steroid cutoffs indicated 21OHD: 3.87 MoM for 17-hydroxyprogesterone (100% sensitivity and 98.83% specificity) and 12.28 MoM for 21-deoxycortisol (94.74% sensitivity and 100% specificity). A cutoff of 13.18 MoM for 11-deoxycortisol indicated 11OHD (100% sensitivity and 100% specificity).

CONCLUSIONS

Age- and sex-independent MoMs are straightforward for a clinically relevant display of multi-steroid patterns. In addition, defined single-steroid MoMs can serve alone as predictors of 21OHD and 11OHD. Finally, MoM transformation offers substantial enhancement of routine and scientific steroid hormone data exchange due to improved comparability.

Gestational intermittent hypoxia increases susceptibility to neuroinflammation and alters respiratory motor control in neonatal rats

Sleep disordered breathing (SDB) and obstructive sleep apnea (OSA) during pregnancy are growing health concerns because these conditions are associated with adverse outcomes for newborn infants. SDB/OSA during pregnancy exposes the mother and the fetus to intermittent hypoxia. Direct exposure of adults and neonates to IH causes neuroinflammation and neuronal apoptosis, and exposure to IH during gestation (GIH) causes long-term deficits in offspring respiratory function. However, the role of neuroinflammation in CNS respiratory control centers of GIH offspring has not been investigated. Thus, the goal of this hybrid review/research article is to comprehensively review the available literature both in humans and experimental rodent models of SDB in order to highlight key gaps in knowledge. To begin to address some of these gaps, we also include data demonstrating the consequences of GIH on respiratory rhythm generation and neuroinflammation in CNS respiratory control regions. Pregnant rats were exposed to daily intermittent hypoxia during gestation (G10-G21). Neuroinflammation in brainstem and cervical spinal cord was evaluated in P0-P3 pups that were injected with saline or lipopolysaccharide (LPS; 0.1mg/kg, 3h). In CNS respiratory control centers, we found that GIH attenuated the normal CNS immune response to LPS challenge in a gene-, sex-, and CNS region-specific manner. GIH also altered normal respiratory motor responses to LPS in newborn offspring brainstem-spinal cord preparations. These data underscore the need for further study of the long-term consequences of maternal SDB on the relationship between inflammation and the respiratory control system, in both neonatal and adult offspring.

The prevalence of obstructive sleep apnea and its association with pregnancy-related health outcomes: a systematic review and meta-analysis

PURPOSE

Obstructive sleep apnea (OSA) is common during pregnancy. Nevertheless, prevalence estimates of OSA have varied widely due to variabilities in the assessment methods. This meta-analysis aimed to examine the prevalence of objectively assessed OSA and its association with pregnancy-related health outcomes in pregnant women.

METHODS

This review was developed following the PRISMA guideline. A systematic search was conducted in major electronic databases to identify studies conducted from inception to January 2018. The pooled estimates with 95% confidence interval were calculated using the inverse variance method. Forest plots were used to present the results of individual studies and the pooled effect sizes.

RESULTS

Thirty-three studies were included. The mean gestational age was between 21.2 (8.5) and 37.3 (2.1) weeks. The pooled worldwide prevalence of OSA was 15% (95% CI 12-18%). The prevalence estimates ranged from 5% in the European Region to 20% in the Region of Americas. The prevalence estimates for different trimesters ranged from 15 to 19%. OSA was related to an increased risk for gestational hypertension, gestational diabetes, pre-eclampsia, C-section, postoperative wound complication, and pulmonary edema. The pooled adjusted odds ratio (aOR) values were 1.97, 1.55, 2.35, 1.42, 1.87, and 6.35, respectively. OSA was also related to an increased risk for preterm birth (aOR = 1.62) and neonatal intensive care unit admission (aOR = 1.28).

CONCLUSIONS

OSA is a common health issue in pregnant women. OSA is associated with various pregnancy-related health outcomes. Routine screening, early diagnosis, and effective treatment of OSA are recommended in pregnant women, particularly during mid and late pregnancy.

The intrapartum and perinatal risks of sleep-disordered breathing in pregnancy: a systematic review and metaanalysis

OBJECTIVE DATA

Sleep-disordered breathing is an increasingly common condition in nonobstetric populations and is associated with significant morbidity. The incidence of sleep-disordered breathing in pregnancy is unknown, and it is likely that many cases go undiagnosed.

STUDY

A systematic review and metaanalysis was undertaken to determine whether pregnant women who receive a diagnosis of sleep-disordered breathing are more likely to have adverse intrapartum and perinatal outcomes compared with control subjects.

STUDY APPRAISAL AND SYNTHESIS METHODS

PubMed, Embase, and Cinahl databases were searched for full-text publications in English of sleep-disordered breathing and human pregnancy up to June 2017. Only studies that reported on sleep-disordered breathing in relation to gestational age or birthweight at delivery, preterm birth, mode of delivery, cord pH, Apgar score, nursery admission, stillbirth or perinatal death, meconium at delivery, or wound complications were included.

RESULTS

A total of 1576 results were identified; 33 studies met inclusion criteria. Women with sleep-disordered breathing were older (mean difference, 1.66; 95% confidence interval, 1.04-2.28) and had a higher body mass index (mean difference, 3.31; 95% confidence interval, 2.30-4.32) than those who did not. Maternal sleep-disordered breathing was associated significantly with preterm birth (<37 weeks gestation; odds ratio, 1.86; 95% confidence interval, 1.50-2.31) and low birthweight (<2500 g; odds ratio, 1.67; 95% confidence interval, 1.00-2.78). These women were also less likely to have a vaginal delivery (odds ratio, 0.61; 95% confidence interval, 0.48-0.78) and to be at a higher risk of having an assisted vaginal delivery (odds ratio, 1.88; 95% confidence interval, 1.10-3.21) or a cesarean delivery (odds ratio, 1.81; 95% confidence interval, 1.55-2.11). The risk of both elective (odds ratio, 1.38; 95% confidence interval, 1.09 - 1.76) and emergency cesarean (odds ratio, 2.52; 95% confidence interval, 1.20-5.29) was increased. In addition, women with sleep-disordered breathing were at a higher risk of having an infant with a 5-minute Apgar score <7 (odds ratio, 2.14; 95% confidence interval, 1.24-3.71), stillbirth or perinatal death (odds ratio, 2.02; 95% confidence interval, 1.25-3.28), and neonatal nursery admission (odds ratio, 1.90; 95% confidence interval, 1.38-2.61).

CONCLUSION

Maternal sleep-disordered breathing is associated with increased risks of adverse intrapartum and perinatal outcomes.

Snoring and markers of fetal and placental wellbeing

INTRODUCTION

Snoring, the symptom of partial airway obstruction during sleep, is a common complaint during pregnancy and is associated with adverse perinatal outcomes. Mechanisms underlying this association have not been studied. We investigated the relationship between snoring in pregnancy and maternal serum markers of feto-placental wellbeing.

METHODS

We conducted a secondary analysis of a cross sectional study designed to investigate perinatal outcomes of sleep-disordered breathing. Women admitted for delivery were systematically selected and answered a questionnaire about snoring using the Multivariable Apnea Prediction Index. Participants who had screening markers measured were included and divided into snorers and non -snorers. Markers measured included first and second trimester Down syndrome screening markers, reported as multiples of the median (MoM). An additional analysis was performed with snorers categorized as acute or chronic snorers based on duration of snoring in relation to pregnancy.

RESULTS

While significant differences were noted in co-morbid maternal medical conditions between snorers and non-snorers, there were no significant differences in the neonatal outcomes assessed between the two groups. No significant differences were noted in any of the first trimester (PAPP-A) or second trimester (AFP, uE3, hCG, inhibin-A) markers between snorers and non-snorers, p > 0.25. In addition, no significant differences in marker levels were noted between acute and chronic snorers.

CONCLUSION

Snoring is not associated with alterations in the markers of fetal or placental wellbeing tested here and suggests that there are alternative mechanisms underlying the association between snoring and adverse perinatal outcomes.

Effect of Gender on Chronic Intermittent Hypoxic Fosb Expression in Cardiorespiratory-Related Brain Structures in Mice

We aimed to delineate sex-based differences in neuroplasticity that may be associated with previously reported sex-based differences in physiological alterations caused by repetitive succession of hypoxemia-reoxygenation encountered during obstructive sleep apnea (OSA). We examined long-term changes in the activity of brainstem and diencephalic cardiorespiratory neuronal populations induced by chronic intermittent hypoxia (CIH) in male and female mice by analyzing Fosb expression. Whereas the overall baseline and CIH-induced Fosb expression in females was higher than in males, possibly reflecting different neuroplastic dynamics, in contrast, structures responded to CIH by Fosb upregulation in males only. There was a sex-based difference at the level of the rostral ventrolateral reticular nucleus of the medulla, with an increase in the number of FOSB/ΔFOSB-positive cells induced by CIH in males but not females. This structure contains neurons that generate the sympathetic tone and which are involved in CIH-induced sustained hypertension during waking hours. We suggest that the sex-based difference in neuroplasticity of this structure contributes to the reported sex-based difference in CIH-induced hypertension. Moreover, we highlighted a sex-based dimorphic phenomenon in serotoninergic systems induced by CIH, with increased serotoninergic immunoreactivity in the hypoglossal nucleus and a decreased number of serotoninergic cells in the dorsal raphe nucleus in male but not female mice. We suggest that this dimorphism in the neuroplasticity of serotoninergic systems predisposes males to a greater alteration of neuronal control of the upper respiratory tract associated with the greater collapsibility of upper airways described in male OSA subjects.

Estradiol Protects Against Cardiorespiratory Dysfunctions and Oxidative Stress in Intermittent Hypoxia

Study Objectives

We tested the hypothesis that estradiol (E2) protects against cardiorespiratory disorders and oxidative stress induced by chronic intermittent hypoxia (CIH) in adult female rats.

Methods

Sprague-Dawley female rats (230-250 g) were ovariectomized and implanted with osmotic pumps delivering vehicle or E2 (0.5 mg/kg/d). After 14 days of recovery, the rats were exposed to CIH (21%-10% O2: 8 h/d, 10 cycles per hour) or room air (RA). After 7 days of CIH or RA exposure, we measured arterial pressures (tail cuff), metabolic rate (indirect calorimetry), minute ventilation, the frequency of sighs and apneas at rest, and ventilatory responses to hypoxia and hypercapnia (whole body plethysmography). We collected the cerebral cortex, brainstem, and adrenal glands to measure the activity of NADPH and xanthine oxidase (pro-oxidant enzymes), glutathione peroxidase, and the mitochondrial and cytosolic superoxide dismutase (antioxidant enzymes) and measured lipid peroxidation and advanced oxidation protein products (markers of oxidative stress).

Results

CIH increased arterial pressure, the frequency of apnea at rest, and the hypoxic and hypercapnic ventilatory responses and reduced metabolic rate. CIH also increased oxidant enzyme activities and decreased antioxidant activity in the cortex. E2 treatment reduced body weight and prevented the effects of CIH.

Conclusions

E2 prevents cardiorespiratory disorders and oxidative stress induced by CIH. These observations may help to better understand the underlying mechanisms linking menopause and occurrence of sleep apnea in women and highlight a potential advantage of hormone therapy.