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

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.

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.

Racial/ethnic disparities in sleep-disordered breathing during pregnancy in the nuMoM2b study

OBJECTIVE

The aim of this study was to assess the prevalence and severity of sleep-disordered breathing (SDB) across racial/ethnic groups in 3702 pregnant people at 6 to 15 and 22 to 31 weeks gestational age, examine whether BMI modifies the association between race/ethnicity and SDB, and investigate whether interventions to reduce weight might reduce racial/ethnic disparities in SDB.

METHODS

Differences by race/ethnicity in SDB prevalence and severity were quantified via linear, logistic, or quasi-Poisson regression. Controlled direct effect was used to estimate whether intervening on BMI would remove/diminish differences by race/ethnicity in SDB severity.

RESULTS

This study comprised 61.2% non-Hispanic White (nHW), 11.9% non-Hispanic Black (nHB), 18.5% Hispanic, and 3.7% Asian people. SDB prevalence was higher for nHB compared with nHW pregnant people at 6 to 15 weeks (odds ratio [OR] 1.81, 95% CI [1.07, 2.97]), whereas at 21 to 32 weeks, Asian pregnant people had a higher SDB prevalence than nHW (OR 2.2, 95% CI [1.1, 4.0]). The severity of SDB differed across racial/ethnic groups in early pregnancy, with nHB pregnant people having a higher apnea-hypopnea index (AHI) (OR 1.35, 95% CI [1.07, 1.69]) compared with nHW. Having overweight/obesity was associated with a higher AHI (β = 2.36, 95% CI [1.97, 2.84]). Controlled direct effect analyses indicated that in early pregnancy, nHB and Hispanic pregnant people would have a lower AHI compared with nHW people had they had normal weight.

CONCLUSIONS

This study extends knowledge on racial/ethnic disparities in SDB to a pregnant population.

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.

The Berlin Questionnaire in pregnancy predominantly identifies obesity

STUDY OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Snoring and depression symptoms in pregnant women

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

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.

Association Between Nausea and Vomiting During Pregnancy and Sleep Quality: Mediating Effect of Depressive Symptoms

Purpose

Nausea and vomiting during pregnancy (NVP) of varying degrees of severity are commonly experienced by pregnant women. This paper explores the association between NVP and poor sleep quality.

Patients and Methods

A cross-sectional study was conducted in an obstetrics clinic. A total of 2494 pregnant women (representing a response rate of 92.7%) completed a self-administered questionnaire.

Results

Of the 2494 participants, the mean sleep duration was 7.76 hours, and 54.3% of them report poor sleep quality (ie, a Pittsburgh Sleep Quality Index global score > 5). In this study, 49.1%, 49.3% and 1.6% women reported mild, moderate, and severe NVP, respectively. Compare with women with mild NVP, women with moderate or severe NVP were more likely to report poor sleep quality (χ ² = 30.16, p < 0.001). After adjusted for demographics and gestational age, moderate and severe NVP were associated with poor sleep quality (adjusted odds ratio (AOR) = 1.66, 95% confidence interval (CI) = 1.40-1.96, and AOR = 2.95, 95% CI = 1.44-6.02, respectively). Moreover, depressive symptoms mediated the association between NVP and poor sleep quality (β = 0.060, p = 0.033, 95% CI = 0.028-0.180).

Conclusion

Our study suggested that moderate and severe NVP increase the risk of poor sleep quality. Further studies are warranted that focus on the mechanisms of the association between NVP and poor sleep quality.

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.