What they are

Obstructive Sleep Apnea (OSA) is the most common type of sleep-related breathing disorder (SRBD) and is characterized by repeated airway closure, commonly associated with snoring, often accompanied by sensations of "choking" and "gasping" during the night. This leads to decreased blood oxygen levels, frequent awakenings, and increased blood pressure and heart rate during sleep (Sommers, 1995).

Prevalence

The prevalence of OSA in the general population ranges from 4% to 32% (Young, 2002; Tufik, 2010; Peppard, 2013; Heinzer, 2015). However, approximately 93% of men and 83% of women with moderate to severe apnea remain undiagnosed (Young, 1997). In women of reproductive age, obstructive sleep apnea presents with few symptoms, making diagnosis difficult. Physiological, anatomical, and hormonal changes during pregnancy may predispose women to the onset of SRBDs or worsen a pre-existing, undiagnosed condition (Facc, 2012; Hedman, 2002).

The prevalence of OSA during pregnancy remains uncertain in international literature and appears to be related to population type, ethnicity, pregnancy risk level (low or high), and gestational period (Fung, 2013; Wilson, 2013). High-risk pregnancy is defined as “one in which the life or health of the mother and/or fetus and/or newborn is more likely to be affected than in the average population,” with high-risk factors including obesity, hypertension, diabetes, maternal age at pregnancy onset, general clinical conditions, and pregnancy-related diseases such as gestational hypertension, preeclampsia, gestational diabetes, among others (CALDEYRO-BARCIA, 1973; High-Risk Pregnancy Manual, Brazilian Ministry of Health, 2017). Some studies show a prevalence of 20% to 35% of SRBDs in high-risk pregnant women (Antony, 2014).

Cause

Recent studies indicate that SRBDs characterized by sleep apnea, snoring, and nighttime respiratory effort—even in the absence of apnea—are associated with maternal and fetal consequences including gestational hypertensive disease (GHD), preeclampsia, gestational diabetes (GDM), and premature low birth weight infants (Guillemineault, 2007; Pamidi, S, 2014; Xu T, 2014).

Diagnosis

Diagnosing SRBDs during pregnancy can help prevent and treat these disorders early, reducing undesirable outcomes. To date, there are no guidelines standardizing or directing the early diagnosis and treatment of SRBDs during pregnancy, despite their potential harmful effects on both mother and fetus. Overnight polysomnography is the test used to diagnose sleep disorders. However, the long wait time for the exam, the limited diagnostic window during pregnancy, the discomfort caused by the sleep test in this population, and the general lack of awareness—both among the public and medical professionals—make investigation difficult or even impossible.

Treatment

CPAP, which is characterized as an airflow generator that maintains continuous positive airway pressure during sleep through a nasal mask, promotes full opening of the collapsed airway region and is the treatment of choice for moderate to severe sleep apnea (Kushida, 2006). CPAP is also indicated for the treatment of sleep-related breathing disorders (SRBDs) in the early stages of pregnancy and is well tolerated in this group (Guilleminault, 2004). However, adherence to CPAP during pregnancy has never been studied (Cornelio, 2016). Recent research using nighttime ventilation in pregnant women with preeclampsia or chronic hypertension has shown a reduction in blood pressure during sleep in preeclamptic women, improved blood pressure control during pregnancy in previously hypertensive patients without the need to change antihypertensive medication, and improved clinical outcomes at birth (Guilleminault, 2004; Guilleminault, 2007; Poyares, 2007).

Studies also show that in pregnant women at increased risk for OSA, treatment with CPAP improves maternal-fetal respiratory conditions. Furthermore, CPAP at low pressures during sleep could serve as an adjunct treatment for all women with gestational hypertension, preeclampsia, and snoring associated with sleep-related breathing difficulties (Guilleminault, 2004; Guilleminault, 2007; Poyares, 2007; Cornelio, 2016).

References

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2. Young T, Peppard PE, Gottlieb DJ. Epidemiology of obstructive sleep apnea: a population health perspective. Am J Respir Crit Care Med. 2002;165

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4. Peppard PE, Young T, Barnet JH, Palta M, Hagen EW, Hla KM. Increased prevalence of sleep-disordered breathing in adults. Am J Epidemiol. 2013;177:1006–1014.

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6. Young T, Evans L, Finn L, Palta M. Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle-aged men and women. Sleep. 1997 Sep;20(9):705-6.

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8. Facco FL, Ouyang DW, Zee PC, Grobman WA. Development of a pregnancy-specific screening tool for sleep apnea. J Clin Sleep Med 2012;8(4):389e94.

9. Hedman C, Pohjasvaara T, Tolonen U, Suhonen-Malm AS, Myllyla VV. Effects of pregnancy on mothers' sleep. Sleep Med 2002;3(1):37e42.

10. Fung AM, Wilson DL, Lappas M, Howard M, Barnes M, O'Donoghue F, et al. Effects of maternal obstructive sleep apnoea on fetal growth: a prospective cohort study. PLoS One 2013;8(7).

11. CALDEYRO-BARCIA, R. et al. Fetal heart rate and acid-base balance. Montevideo: Latin American Center for Perinatology and Human Development, 1973. (CLAP Scientific Publication, No. 519).

12. High-Risk Pregnancy: Technical Manual / Ministry of Health, Secretariat of Health Care, Department of Strategic Programmatic Actions. – 5th ed. – Brasília: Ministry of Health Publishing House, 2010. 302 p. – (Series A. Standards and Technical Manuals)

13. Wilson DL, Walker SP, Fung AM, O'Donoghue F, Barnes M, Howard M. Can we predict sleep-disordered breathing in pregnancy? The clinical utility of symptoms. J Sleep Res 2013;22(6):670e8.

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15. Guilleminault C, Palombini L, Poyares D, Takaoka S, Huynh NT, El-Sayed Y. Pre-eclampsia and nasal CPAP: part 1. Early intervention with nasal CPAP in pregnant women with risk-factors for pre-eclampsia: preliminary findings. Sleep Med 2007;9(1):9e14

16. Pamidi S, Pinto LM, Marc I, Benedetti A, Schwartzman K, Kimoff RJ. Maternal sleep-disordered breathing and adverse pregnancy outcomes: a systematic review and meta-analysis. Am J Obstetrics Gynecol 2014;210(1):52. e1ee14

17. Xu T, Feng Y, Peng H, Guo D, Li T. Obstructive sleep apnea and the risk of perinatal outcomes: a meta-analysis of cohort studies. Sci Rep 2014;4.

18. Kushida AC, Littner MR, Hirshkowitz M, et al. Practice Parameters for the Use of Continuous and Bilevel Positive Airway. Pressure Devices to Treat Adult Patients With Sleep-Related Breathing Disorders. Sleep 2006;29:375-380.

19. Guilleminault C, Kreutzer M, Chang JL. Pregnancy, sleep disordered breathing and treatment with nasal continuous positive airway pressure. Sleep Med 2004;5(1):43e51

20. Carnelio S, Morton A, McIntyre HD. Sleep disordered breathing in pregnancy: the maternal and fetal implications. J Obstet Gynaecol. 2017 Feb;37(2):170-178.

21. Guilleminault C, Palombini L, Poyares D, Takaoka S, Huynh NT, El-Sayed Y. Pre-eclampsia and nasal CPAP: part 1. Early intervention with nasal CPAP in pregnant women with risk-factors for pre-eclampsia: preliminary findings. Sleep Med 2007;9(1):9e14.

22. Poyares D, Guilleminault C, Hachul H, Fujita L, Takaoka S, Tufik S, et al. Preeclampsia and nasal CPAP: part 2. Hypertension during pregnancy, chronic snoring, and early nasal CPAP intervention. Sleep Med 2007;9(1):15e21.

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By Einstein Editorial Board