Sleep disordered breathing controlled by CPAP and sFlt-1 in a pregnant patient with chronic hypertension: Case report and literature review

Continuous Positive Airway Pressure Treatment and Hypertensive Adverse Outcomes in Pregnancy: A Systematic Review and Meta-Analysis

Importance

Pregnancy may contribute to the development or exacerbation of obstructive sleep apnea (OSA) and increase the risk of gestational complications. Continuous positive airway pressure (CPAP) is the first-line and criterion standard treatment for OSA and is regarded as the most feasible choice during pregnancy. However, the association between CPAP therapy in pregnant women with OSA and reduced gestational complications remains inconclusive.

Objective

To investigate the association between CPAP therapy in pregnant women with OSA and the reduction of adverse hypertensive outcomes during gestation.

Data Sources

Keyword searches of PubMed, Embase, and the Cochrane Database of Systematic Reviews and Clinical Trials were conducted from inception to November 5, 2023.

Study Selection

Original studies reporting the treatment effect of CPAP use on lowering hypertension and preeclampsia risks in pregnant women with OSA were selected.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed in the reporting of reviews. Data were independently extracted by 2 authors. Random-effects model meta-analyses were performed and risk ratios (RRs) reported. Subgroup analysis, meta-regression based on age and body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), and publication bias assessment were also conducted.

Main Outcome and Measures

The primary outcome was the RR of gestational hypertension and preeclampsia between pregnant women with OSA receiving CPAP treatment and those who did not receive CPAP treatment.

Results

Six original studies in 809 participants (mean age, 31.4 years; mean BMI, 34.0) were identified and systematically reviewed for meta-analysis. The pooled results showed significant differences between the intervention (CPAP use) and the control (non-CPAP use) groups in reducing the risk of gestational hypertension (RR, 0.65; 95% CI, 0.47-0.89; P = .008) and preeclampsia (RR, 0.70; 95% CI, 0.50-0.98; P = .04). Meta-regression revealed that patients' age (coefficient, -0.0190; P = .83) and BMI (coefficient, -0.0042; P = .87) were not correlated with reduction of risk of hypertension and preeclampsia.

Conclusions and Relevance

These findings suggest that implementing CPAP treatment in pregnant women with OSA may reduce the risk of gestational hypertension and preeclampsia.

Treatment of obstructive sleep apnea in high risk pregnancy: a multicenter randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) during pregnancy is a risk factor for preeclampsia possibly through a link to placental physiology. This study evaluates the efficacy of continuous positive airway pressure (CPAP) on the modulation of blood pressure and the reduction in preeclampsia in women with high-risk pregnancy and OSA.

METHODS

A multicenter open-label, randomized controlled trial comparing CPAP treatment versus usual antenatal care was conducted in three academic hospitals in Bangkok, Thailand. Participants included singleton pregnant women aged older than 18 years with any high-risk condition (i.e., chronic hypertension, obesity, history of preeclampsia or gestational diabetes in the previous pregnancy, or diabetes), and OSA (respiratory disturbance index 5-29.99 events/hour by polysomnography), who presented either in the first trimester (gestational age, GA 0-16 weeks) or subsequently developed OSA during the 2nd trimester (GA 24-28 weeks). The primary endpoint was blood pressure during antenatal care. Secondary endpoints included the incidence of preeclampsia. An intention-to-treat analysis was performed with additional per-protocol and counterfactual analyses for handling of nonadherence.

RESULTS

Of 340 participants, 96.5% were recruited during the first trimester. Thirty participants were later excluded leaving 153 and 157 participants in the CPAP and usual-care groups for the modified-intention-to-treat analysis. CPAP adherence rate was 32.7% with average use of 2.5 h/night. Overall, CPAP treatment significantly lowered diastolic blood pressure (DBP) by - 2.2 mmHg [95% CI (- 3.9, - 0.4), p = 0.014], representing approximately - 0.5 mmHg per hour of CPAP use [95%CI (- 0.89, - 0.10), p = 0.013]. CPAP treatment also altered the blood pressure trajectory by continuously lowering DBP throughout pregnancy with mean differences (95% CI) of - 3.09 (- 5.34, - 0.93), - 3.49 (- 5.67, - 1.31) and - 3.03 (- 5.20, - 0.85) mmHg at GA 18-20, 24-28, and 32-34 weeks, respectively compared to 0-16 weeks. Preeclampsia rate was 13.1% (20/153 participants) in the CPAP and 22.3% (35/157 participants) in the usual-care group with a risk difference (95% CI) of - 9% (- 18%, - 1%, p-value = 0.032) and a number-needed-to-treat (95% CI) of 11 (1, 21).

CONCLUSIONS

CPAP treatment in women with even mild-to-moderate OSA and high-risk pregnancy demonstrated reductions in both DBP and the incidence of preeclampsia. CPAP treatment also demonstrated a sustained reduction in DBP throughout gestation. Trial registration ClinicalTrial.GovNCT03356106, retrospectively registered November 29, 2017.

A randomized controlled trial of sleep study surveillance with targeted autoregulated positive airway pressure therapy for obstructive sleep apnea in pregnancy

BACKGROUND

Obstructive sleep apnea is associated with adverse pregnancy outcomes. The impact therapy for obstructive sleep apnea has on these pregnancy outcomes remains under investigated.

OBJECTIVE

This study aimed to determine the effects of targeted autoregulated positive airway pressure in women at risk of obstructive sleep apnea on adverse pregnancy outcomes, cost, and natural history of obstructive sleep apnea.

STUDY DESIGN

Pregnant women at high risk of obstructive sleep apnea were randomized to either a sleep study screening group receiving autoregulated positive airway therapy or a group not screened for obstructive sleep apnea receiving standard obstetrical care (control). Women in the sleep study-screened group received a sleep study at 2 periods during pregnancy, early (6-16 weeks of gestation) and late (27-33 weeks of gestation), with initiation of autoregulated positive airway therapy if their Apnea Hypopnea Index indicated ≥5 events per hour. Women of both groups had a sleep study 3 months after delivery. The primary outcome was effect on adverse pregnancy outcomes, a composite of hypertension, preterm birth, low birthweight, stillbirth, and diabetes mellitus. The secondary outcomes included obstructive sleep apnea severity and hospital costs.

RESULTS

Among 193 women randomized (100 in the sleep study-screened group and 93 in the control group; 6 lost to follow-up), there was no significant difference in composite adverse pregnancy outcomes (46.4% screened vs 43.3% control; P=.77), hypertension (23.7% screened vs 32.0% control; P=.25), preterm birth (13.4% screened vs 10.0% control; P=.5), low birthweight (5.2% screened vs 6.7% control; P=.76), stillbirth (1% screened vs 0% control; P=1), gestational diabetes (19.6% screened vs 13.3% control; P=.33), or mean cost ($12,185 screened vs $12,607 control). The Apnea Hypopnea Index increased throughout pregnancy, peaking at 3 months after delivery (P<.001). There were 24 subjects (25.8%) who had a new diagnosis of obstructive sleep apnea, with 6 in whom autoregulated positive airway was prescribed. The autoregulated positive airway compliance rates were poor with usage rates ranging from 2% (1 of 64 days) to 43% (6 of 14 days).

CONCLUSION

Targeted autoregulated positive airway therapy for obstructive sleep apnea did not decrease composite adverse pregnancy outcomes or hospital costs in the sleep study-screened high-risk pregnancy group compared with the group that received no obstructive sleep apnea screening. However, a small sample size, low autoregulated positive airway prescription rates, and poor compliance resulted in difficulty in drawing a definitive conclusion. The prevalence and severity of obstructive sleep apnea worsened throughout pregnancy, with the highest rates detected in the postpartum period. Large, multicenter clinical trials that are adequately powered are needed.

The etiology of preeclampsia

Preeclampsia is one of the "great obstetrical syndromes" in which multiple and sometimes overlapping pathologic processes activate a common pathway consisting of endothelial cell activation, intravascular inflammation, and syncytiotrophoblast stress. This article reviews the potential etiologies of preeclampsia. The role of uteroplacental ischemia is well-established on the basis of a solid body of clinical and experimental evidence. A causal role for microorganisms has gained recognition through the realization that periodontal disease and maternal gut dysbiosis are linked to atherosclerosis, thus possibly to a subset of patients with preeclampsia. The recent reports indicating that SARS-CoV-2 infection might be causally linked to preeclampsia are reviewed along with the potential mechanisms involved. Particular etiologic factors, such as the breakdown of maternal-fetal immune tolerance (thought to account for the excess of preeclampsia in primipaternity and egg donation), may operate, in part, through uteroplacental ischemia, whereas other factors such as placental aging may operate largely through syncytiotrophoblast stress. This article also examines the association between gestational diabetes mellitus and maternal obesity with preeclampsia. The role of autoimmunity, fetal diseases, and endocrine disorders is discussed. A greater understanding of the etiologic factors of preeclampsia is essential to improve treatment and prevention.