Effects of maternal obstructive sleep apnea on fetal growth: a case-control study

Influence of Obstructive Sleep Apnea on Oxidative Stress in Pregnancy

Obstructive sleep apnea (OSA) is common during pregnancy and linked to adverse outcomes. While oxidative stress is a proposed pathogenic mechanism, evidence in pregnant populations remains limited. This multicenter, prospective study evaluated oxidative stress through protein carbonyl levels in 171 pregnant women and 86 cord blood samples. Polysomnography (PSG) performed during pregnancy categorized participants with the apnea-hypopnea index (AHI) in OSA, rapid eye movement (REM) OSA, and supine OSA. Protein carbonyl levels were measured by the dinitrophenyl hydrazine (DNPH) method. No significant differences were found in maternal or cord blood protein carbonyl levels between OSA and non-OSA groups, or between REM and supine OSA subgroups. Interestingly, women with shorter apnea-hypopnea (AH) length showed both higher maternal and cord blood protein carbonyl levels and lower nocturnal oxygen saturation. Overall, OSA in pregnancy was not associated with increased oxidative stress as measured by protein carbonyl levels. However, apnea-hypopnea duration and nocturnal hypoxia may influence oxidative stress, pointing to a complex relationship between OSA and oxidative stress during pregnancy, beyond traditional metrics like AHI. Future studies should explore additional biomarkers and diverse molecular pathways that could play a role, with special attention to emerging factors such as apnea-hypopnea length and hypoxic burden to elucidate the interrelationships between OSA and pregnancy more comprehensively.

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.

Sleep duration, napping behaviors and restless legs syndrome during pregnancy and the trajectories of ultrasonographic measures of fetal growth: Findings from the NICHD Fetal Growth Studies-Singletons

OBJECTIVES

Given the plausible mechanisms and the lacking of empirical evidence, the study aims to investigate how gestational sleep behaviors and the development of sleep disorders, such as restless legs syndrome, influence ultrasonographic measures of fetal growth.

METHODS

The study included 2457 pregnant women from the NICHD Fetal Growth Studies - Singletons (2009-2013), who were recruited between 8-13 gestational weeks and followed up to five times during pregnancy. Women were categorized into six groups based on their total sleep hours and napping frequency. The trajectory of estimated fetal weight from 10-40weeks was derived from three ultrasonographic measures. Linear mixed effect models were applied to model the estimated fetal weight in relation to self-reported sleep-napping behaviors and restless legs syndrome status, adjusting for age, race and ethnicity, education, parity, prepregnancy body mass index category, infant sex, and prepregnancy sleep-napping behavior.

RESULTS

From enrollment to near delivery, pregnant women's total sleep duration and nap frequency declined and restless legs syndrome symptoms frequency increased generally. No significant differences in estimated fetal weight were observed by sleep-napping group or by restless legs syndrome status. Results remained similar in sensitivity analyses and stratified analyses by women's prepregnancy body mass index category (normal vs. overweight/obese) or by infant sex.

CONCLUSIONS

Our data indicate that there is no association between sleep during pregnancy-assessed as total sleep duration and napping frequency, nor restless legs syndrome symptoms-and fetal growth from weeks 10 to 40 in healthy pregnant women.

Gestational intermittent hypoxia reduces mandibular growth with decreased Sox9 expression and increased Hif1a expression in male offspring rats

Introduction

Maternal obstructive sleep apnea (OSA) during pregnancy is the risk factor for impaired fetal growth with low birth weight in the offspring. However, it is unclear whether gestational intermittent hypoxia (IH, a hallmark of maternal OSA) has long-term detrimental consequences on the skeletal development of offspring. This study aimed to investigate postnatal maxillofacial bone growth and cartilage metabolism in male and female offspring that were exposed to gestational IH.

Methods

Mother rats underwent IH at 20 cycles/h (nadir, 4% O2; peak, 21% O2; 0% CO2) for 8 h per day during gestational days (GD) 7-20, and their male and female offspring were analyzed postnatally at 5 and 10 weeks of age. All male and female offspring were born and raised under normoxic conditions.

Results

There was no significant difference in whole-body weight and tibial length between the IH male/female offspring and their control counterparts. In contrast, the mandibular condylar length was significantly shorter in the IH male offspring than in the control male offspring at 5 and 10 weeks of age, while there was no significant difference in the female offspring. Real-time polymerase chain reaction (PCR) showed that gestational IH significantly downregulated the mRNA level of SOX9 (a chondrogenesis marker) and upregulated the mRNA level of HIF-1α (a hypoxia-inducible factor marker) in the mandibular condylar cartilage of male offspring, but not in female offspring.

Conclusion

Gestational IH induced underdeveloped mandibular ramus/condyles and reduced mRNA expression of SOX9, while enhancing mRNA expression of HIF-1α in a sex-dependent manner.

Effect of Obstructive Sleep Apnea during Pregnancy on Fetal Development: Gene Expression Profile of Cord Blood

Obstructive sleep apnea (OSA) is quite prevalent during pregnancy and is associated with adverse perinatal outcomes, but its potential influence on fetal development remains unclear. This study investigated maternal OSA impact on the fetus by analyzing gene expression profiles in whole cord blood (WCB). Ten women in the third trimester of pregnancy were included, five OSA and five non-OSA cases. WCB RNA expression was analyzed by microarray technology to identify differentially expressed genes (DEGs) under OSA conditions. After data normalization, 3238 genes showed significant differential expression under OSA conditions, with 2690 upregulated genes and 548 downregulated genes. Functional enrichment was conducted using gene set enrichment analysis (GSEA) applied to Gene Ontology annotations. Key biological processes involved in OSA were identified, including response to oxidative stress and hypoxia, apoptosis, insulin response and secretion, and placental development. Moreover, DEGs were confirmed through qPCR analyses in additional WCB samples (7 with OSA and 13 without OSA). This highlighted differential expression of several genes in OSA (EGR1, PFN1 and PRKAR1A), with distinct gene expression profiles observed during rapid eye movement (REM)-OSA in pregnancy (PFN1, UBA52, EGR1, STX4, MYC, JUNB, and MAPKAP). These findings suggest that OSA, particularly during REM sleep, may negatively impact various biological processes during fetal development.

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

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

Sleep-disordered breathing and pregnancy outcomes: The impact of maternal oxygen saturation

OBJECTIVE

To investigate pathological associations between sleep-disordered breathing (SDB) and pregnancy outcomes.

METHODS

From May 2016 to September 2019, obese women during their uncomplicated singleton pregnancies underwent screening sleep questionnaires, oxygen saturation monitoring, and, in proper cases, complete overnight polysomnography. Their medical records were also recorded.

RESULTS

In all, 112 pregnant women were included in the study cohort; 44 showed an oxygen desaturation index ≥10, and their newborns had a significantly higher rate of congenital abnormalities and respiratory distress syndrome compared with the women with normal pulse oximetry. Stepwise multivariate regression analysis showed that basal oxygen saturation was independently associated with the occurrence of fetal growth restriction.

CONCLUSION

Among obese pregnant women, the rate of congenital abnormalities is higher in the ones with altered pulse oximetry. Maternal basal oxygen saturation in the first trimester of pregnancy predicts fetal growth restriction independently of maternal age, ethnicity, body mass index, gravidity, and hypertensive disorders of pregnancy.

A Relation between Obstructive Sleep Apnea in Pregnancy and Delivering Small for Gestational Age Infant-A Systematic Review

Obstructive sleep apnea (OSA) during pregnancy can negatively affect both the mother and the baby. Our main goal is to show whether there is an association between OSA during pregnancy and delivering small for gestational age (SGA) infants. This systematic review was conducted according to the PRISMA 2020 statement using three databases: MEDLINE via PubMed, Scopus, and Cochrane Library. All databases were last accessed on 1 June 2023. The implemented systematic literature search identified 744 articles. After excluding reviews, meta-analyses, book chapters, case reports, and letters, 47 studies were analyzed, 18 of which finally met the inclusion criteria. The included studies mainly indicate that OSA during pregnancy may not significantly impact SGA, but some of them have shown the existence of this relation. Nevertheless, it is recommended that all pregnant women should be screened for symptoms of OSA and that sleep tests should be performed on those who show signs of it. Detecting and treating OSA early in pregnancy can help reduce the condition's negative effects. However, more extensive studies are still needed to gather clear evidence on the impact of an OSA diagnosis on mothers and babies.

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.

Fetal growth restriction and stillbirth: Biomarkers for identifying at risk fetuses

Fetal growth restriction (FGR) is a major cause of stillbirth, prematurity and impaired neurodevelopment. Its etiology is multifactorial, but many cases are related to impaired placental development and dysfunction, with reduced nutrient and oxygen supply. The fetus has a remarkable ability to respond to hypoxic challenges and mounts protective adaptations to match growth to reduced nutrient availability. However, with progressive placental dysfunction, chronic hypoxia may progress to a level where fetus can no longer adapt, or there may be superimposed acute hypoxic events. Improving detection and effective monitoring of progression is critical for the management of complicated pregnancies to balance the risk of worsening fetal oxygen deprivation in utero, against the consequences of iatrogenic preterm birth. Current surveillance modalities include frequent fetal Doppler ultrasound, and fetal heart rate monitoring. However, nearly half of FGR cases are not detected in utero, and conventional surveillance does not prevent a high proportion of stillbirths. We review diagnostic challenges and limitations in current screening and monitoring practices and discuss potential ways to better identify FGR, and, critically, to identify the “tipping point” when a chronically hypoxic fetus is at risk of progressive acidosis and stillbirth.

Burden of sleep disturbance in non-Hispanic Black pregnant women

STUDY OBJECTIVES

Non-Hispanic Black pregnant women disproportionately experience poor perinatal outcomes compared to other racial/ethnic groups. Sleep disruption has emerged as a risk factor for adverse pregnancy outcomes, but there are limited data in minority pregnant women. We examined the prevalence of habitual snoring and its timing of onset with several key sleep-wake disturbances and their associations with perinatal outcomes in a cohort of non-Hispanic Black pregnant women.

METHODS

Non-Hispanic Black pregnant women in their third trimester were recruited from a large academic medical center and screened for habitual snoring and its timing relative to pregnancy, along with sleep quality, symptoms of insomnia, excessive daytime sleepiness, and daytime function. Clinical diagnoses of hypertensive disorders of pregnancy were obtained along with delivery outcomes.

RESULTS

In 235 women, the vast majority (80%) reported 3 or more sleep-wake disturbances, and almost half had at least 5 disturbances. Sixteen percent reported prepregnancy snoring and 20% reported pregnancy-onset snoring. Women with pregnancy-onset snoring had significantly increased odds of poor sleep quality (adjusted odds ratio [aOR] = 8.2), trouble staying asleep (aOR = 3.6), waking up too early (aOR = 2.7), excessive daytime sleepiness (aOR = 2.3), and poor daytime function (aOR = 8.7) but no relationship with perinatal outcomes. In contrast, prepregnancy snoring was related to chronic hypertension, preterm delivery, and fetal growth restriction (aOR = 2.6, aOR = 2.8, and aOR = 5.1, respectively).

CONCLUSIONS

Sleep-wake disturbances confer a significant burden to pregnant non-Hispanic Black women, an infrequently studied yet disproportionately affected population. Contributions of maternal sleep to racial disparities in perinatal health should be a priority for public health research.

CITATION

White KM, Dunietz GL, Pitts DS, Kalmbach DA, Lucchini M, O'Brien LM. Burden of sleep disturbance in non-Hispanic Black pregnant women. J Clin Sleep Med. 2022;18(5):1319-1325.

Maternal and fetal outcomes in pregnancies with obstructive sleep apnea

OBJECTIVES

Obstructive sleep apnea (OSA) is linked to many health comorbidities. We aimed to ascertain if OSA correlates with a rise in poor obstetrical outcomes.

METHODS

Employing the United States' Healthcare Cost and Utilization Project - National Inpatient Sample, we performed our retrospective cohort study including all women who delivered between 2006 and 2015. ICD-9 codes were used to characterize women as having a diagnosis of OSA. Temporal trends in pregnancies with OSA were studied, baseline features were evaluated among gravidities in the presence and absence of OSA, and multivariate logistic regression analysis was utilized in assessing consequences of OSA on patient and newborn outcomes.

RESULTS

Of a total 7,907,139 deliveries, 3,115 belonged to patients suffering from OSA, resulting in a prevalence of 39 per 100,000 deliveries. Rates rose from 10.14 to 78.12 per 100,000 deliveries during the study interval (p<0.0001). Patients diagnosed with OSA were at higher risk of having pregnancies with preeclampsia, OR 2.2 (95% CI 2.0-2.4), eclampsia, 4.1 (2.4-7.0), chorioamnionitis, 1.4 (1.2-1.8), postpartum hemorrhage, 1.4 (1.2-1.7), venous thromboembolisms, 2.7 (2.1-3.4), and to deliver by caesarean section, 2.1 (1.9-2.3). Cardiovascular and respiratory complications were also more common among these women, as was maternal death, 4.2 (2.2-8.0). Newborns of OSA patients were at elevated risk of being premature, 1.3 (1.2-1.5) and having congenital abnormalities, 2.3 (1.7-3.0).

CONCLUSIONS

Pregnancies with OSA were linked to an elevated risk of poor maternal and neonatal outcomes. During pregnancy, OSA patients should receive attentive follow-up care in a tertiary hospital.

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.

Snoring and depression symptoms in pregnant women

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

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.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

The presence of coexisting sleep-disordered breathing among women with hypertensive disorders of pregnancy does not worsen perinatal outcome

Objective

To determine whether the presence of co-existing sleep-disordered breathing (SDB) is associated with worse perinatal outcomes among women diagnosed with a hypertensive disorder of pregnancy (HDP), compared with normotensive controls.

Study design

Women diagnosed with HDP (gestational hypertension or preeclampsia) and BMI- and gestation-matched controls underwent polysomnography in late pregnancy to determine if they had coexisting SDB. Fetal heart rate (FHR) monitoring accompanied the sleep study, and third trimester fetal growth velocity was assessed using ultrasound. Cord blood was taken at delivery to measure key regulators of fetal growth.

Results

SDB was diagnosed in 52.5% of the HDP group (n = 40) and 38.1% of the control group (n = 42); p = .19. FHR decelerations were commonly observed during sleep, but the presence of SDB did not increase this risk in either the HDP or control group (HDP group—SDB = 35.3% vs. No SDB = 40.0%, p = 1.0; control group—SDB = 41.7% vs. No SDB = 25.0%, p = .44), nor did SDB affect the total number of decelerations overnight (HDP group—SDB = 2.7 ± 1.0 vs. No SDB = 2.8 ± 2.1, p = .94; control group—SDB = 2.0 ± 0.8 vs. No SDB = 2.0 ± 0.7, p = 1.0). Fetal growth restriction was the strongest predictor of fetal heart rate events during sleep (aOR 5.31 (95% CI 1.26–22.26), p = .02). The presence of SDB also did not adversely affect fetal growth; in fact among women with HDP, SDB was associated with significantly larger customised birthweight centiles (43.2% ± 38.3 vs. 16.2% ± 27.0, p = .015) and fewer growth restricted babies at birth (30% vs. 68.4%, p = .026) compared to HDP women without SDB. There was no impact of SDB on measures of fetal growth for the control group. Cord blood measures of fetal growth did not show any adverse effect among women with SDB, either in the HDP or control group.

Conclusion

We did not find that the presence of mild SDB worsened fetal acute or longitudinal outcomes, either among women with HDP or BMI-matched normotensive controls. Unexpectedly, we found the presence of SDB conferred a better prognosis in HDP in terms of fetal growth. The fetus has considerable adaptive capacity to withstand in utero hypoxia, which may explain our mostly negative findings. In addition, SDB in this cohort was mostly mild. It may be that fetal sequelae will only be unmasked in the setting of more severe degrees of SDB and/or underlying placental disease.

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.

Gestational intermittent hypoxia induces endothelial dysfunction, reduces perivascular adiponectin and causes epigenetic changes in adult male offspring

KEY POINTS

Obstructive sleep apnoea (OSA) is characterized by intermittent hypoxia, which causes oxidative stress and inflammation and increases the risk of cardiovascular disease. OSA during pregnancy causes adverse maternal and fetal outcomes. The effects of pre-existing OSA in pregnant women on cardiometabolic outcomes in the offspring are unknown. We evaluated basic metabolic parameters, as well as aortic vascular and perivascular adipose tissue (PVAT) function in response to adiponectin, and examined DNA methylation of adiponectin gene promoter in PVAT in 16-week-old adult offspring exposed to gestational intermittent hypoxia (GIH). GIH decreased body weights at week 1 in both male and female offspring, and caused subsequent increases in body weight and food consumption in male offspring only. Adult female offspring had normal levels of lipids, glucose and insulin, with no endothelial dysfunction. Adult male offspring exhibited dyslipidaemia, insulin resistance and hyperleptinaemia. Decreased endothelial-dependent vasodilatation, loss of anti-contractile activity of PVAT and low circulating PVAT adiponectin levels, as well as increased pro-inflammatory gene expression and DNA methylation of adiponectin gene promoter, occurred in adult male offspring. Our results suggest that male offspring of women with OSA could be at risk of developing cardiometabolic disease during adulthood.

ABSTRACT

Perturbations during pregnancy can program the offspring to develop cardiometabolic diseases later in life. Obstructive sleep apnoea (OSA) is a chronic condition that frequently affects pregnancies and leads to adverse fetal outcomes. We assessed the offspring of female mice experiencing gestational intermittent hypoxia (GIH), a hallmark of OSA, for changes in metabolic profiles, aortic nitric oxide (NO)-dependent relaxations, perivascular adipose tissue (PVAT) anti-contractile activities and the responses to adiponectin, and DNA methylation of the adiponectin gene promoter in PVAT tissue. Pregnant mouse dams were exposed to intermittent hypoxic cycles ( F I O 2 21-12%) for 18 days. GIH resulted in lower body weights of pups at week 1, followed by significant weight gain by week 16 of age in male but not female offspring. Plasma lipids, leptin and insulin resistance were higher in GIH male adult offspring. Endothelium-dependent relaxation in response to ACh and the anti-contractile activity of PVAT in the abdominal aorta was reduced in GIH adult male offspring. Incubation of arteries from GIH adult male offspring with adiponectin restored the anti-contractile activity of PVAT. Both circulating and PVAT tissue homogenate levels of adiponectin, as well as gene expression of adiponectin in PVAT, were lower in GIH male offspring, along with an increased gene expression of inflammatory cytokines. Pyrosequencing of adiponectin gene promoter in PVAT showed increased DNA methylation in GIH male offspring. Our results indicate that GIH leads to vascular disease in adult male offspring through PVAT dysfunction, which was associated with low adiponectin levels and epigenetic modifications on the adiponectin gene promoter.

Intermittent hypoxia impairs uterine artery function in pregnant mice

KEY POINTS

Obstructive sleep apnoea (OSA) is a chronic condition characterized by intermittent hypoxia that induces oxidative stress and inflammation leading to cardiovascular disease. Women can develop OSA during late pregnancy, which is associated with adverse maternal and fetal outcomes. However, the effects of OSA throughout pregnancy on fetoplacental outcomes are unknown. Using a mouse model of intermittent hypoxia, we evaluated main uterine artery function, spiral artery remodelling, circulating angiogenic and anti-angiogenic factors, and placental hypoxia and oxidative stress at gestational day 14.5 in pregnant mice. Gestational intermittent hypoxia increased placental weight but decreased fetal weight, impaired uterine artery function, increased circulating angiogenic and anti-angiogenic factors, and induced placental hypoxia and oxidative stress, but had no impact on spiral artery remodelling. Our results suggest that pregnant women experiencing OSA during pregnancy could be at risk of maternal and fetal complications.

ABSTRACT

Obstructive sleep apnoea (OSA) is characterized by chronic intermittent hypoxia (IH) and is associated with increased inflammation, oxidative stress and endothelial dysfunction. OSA is a common sleep disorder and remains under-diagnosed; it can increase the risk of adverse maternal and fetal outcomes in pregnant women. We investigated the effects of gestational IH (GIH) on uterine artery function, spiral artery remodelling and placental circulating angiogenic and anti-angiogenic factors in pregnant female mice. WT C57BL/6 mice (8 weeks) were exposed to either GIH ( F I O 2 12%) or intermittent air ( F I O 2 21%) for 14.5 days of gestation. Exposure to GIH reduced fetal weight but increased placental weight. GIH dams had higher plasma levels of oxidative stress (8-isoprostane) and inflammatory markers (tumour necrosis factor-α). GIH significantly reduced uterine artery function as indicated by reduced endothelium-dependent vasodilatation and enhanced vasoconstriction. Plasma levels of placental angiogenic and anti-angiogenic markers (soluble fms-like tyrosine kinase-1, soluble endoglin, angiogenic placental growth factor-2 and vascular endothelial growth factor) were higher in pregnant mice exposed to GIH. There was no evidence of impaired spiral artery remodelling based on immunostaining with α-smooth muscle actin and cytokeratin-7, and also by measurements of lumen area. Immunostaining for markers of hypoxia (pimonidazole) and oxidative stress (4-hydroxynonenal) were higher in mice exposed to GIH. Our data show that GIH adversely affects uterine vascular function and may be a mechanism by which gestational OSA leads to adverse maternal and fetal outcomes.

No longer rare diseases and obstetric anesthesia

PURPOSE OF REVIEW

With new medical technologies and changing life styles, maternal demographics has changes and consequently older and sicker women are becoming pregnant.In this review, we present these different high-risk parturient populations, which were once considered rare for the practicing obstetric anesthesiologist.

RECENT FINDINGS

With lifestyle and medical advances, older and sicker women are getting pregnant. Older women are more prone to pregnancy complications. Cancer survivors are becoming pregnant and more pregnant women are being diagnosed with cancer. Previous neurological and cardiac conditions considered not compatible with pregnancy are now seen more frequently. As the rate of obesity increases so does the rate of obstructive sleep apnea, which is known to be associated with many adverse maternal and neonatal sequalae. Finally, increased use of both opioids and marijuana has led to increased number of pregnant women using these illicit substances.

SUMMARY

Future research and implementation of international guidelines for management of these high-risk parturient population is necessary in order to reduce maternal and neonatal morbidity.

Maternal obstructive sleep apnea and neonatal birth outcomes in a population based sample

OBJECTIVE

Evaluate the association of OSA with birth outcomes including the risk of congenital anomalies and the need for a higher level of clinical care at delivery.

METHODS

Population-based study that linked newborn records with maternal records. Data from 95 perinatal centers across all geographic census divisions of the U.S. of women with a delivery diagnosis from 2010 to 2014 whose records could be linked to the corresponding newborn record. An International Classification of Diseases, ninth Revision (ICD-9) code for sleep apnea was used to identify exposure and outcome variables. Univariate and multivariate logistic regression analyses were performed with a model that included substance use, obesity, diabetes, maternal co-morbidities, and pregnancy complications.

RESULTS

In this study, 1,423,099 maternal records were linked to live newborn records. OSA was associated with a higher risk for congenital anomalies in offspring (aOR 1.26, 1.11 to 1.43), with the highest risk being that of musculoskeletal anomalies (aOR 1.89, 1.16 to 3.07) after adjusting for comorbidities and potential teratogens. Neonates born to mothers with OSA were more likely to be admitted to the intensive care unit (25.3% vs. 8.1%, p < 0.001), require resuscitation (aOR 2.76, 1.35 to 5.64) and have a longer hospital stay (aOR 2.25, 1.85 to 2.65).

CONCLUSIONS

Although our study does not establish causation, it is the first to demonstrate a higher risk of congenital anomalies and resuscitation at birth in neonates of mothers with OSA, emphasizing the importance of identifying OSA in pregnant women and women of reproductive age.