Many changes in the respiratory system occur during pregnancy, which can alter respiratory function during sleep, increasing the incidence and severity of sleep-disordered breathing. A recent study suggests that mid-gestational sleep-disordered breathing (SDB) in high-risk pregnant women was associated with greater arterial stiffness throughout gestation and increased preeclampsia risk. The study findings were published in the American Journal of Obstetrics & Gynecology on December 01, 2021.
Impaired vascular function is a central feature of pathologic processes preceding the onset of preeclampsia. Studies have shown that sleep-disordered breathing in pregnancy has been associated with an increased risk for preeclampsia. However, it is unknown if sleep-disordered breathing is associated with elevated arterial stiffness in pregnancy. Therefore, Dr Stella S. Daskalopoulou and her team conducted a study to evaluate arterial stiffness in pregnant women with and without sleep-disordered breathing and assess the interaction between arterial stiffness, sleep-disordered breathing, and preeclampsia risk.
It was a prospective observational cohort study in which the researchers included a total of 181 high-risk pregnant women at 10-13 weeks' gestation and completed the Epworth Sleepiness Score, Pittsburgh Sleep Quality Index, and Restless Legs Syndrome questionnaires each trimester. They determined sleep-disordered breathing as loud snoring or witnessed apneas (≥3 times/week). They assessed the following measures non-invasively using applanation tonometry at recruitment and every four weeks from recruitment until delivery.
◊ Central arterial stiffness (carotid-femoral pulse wave velocity, the gold standard measure of arterial stiffness),
◊Peripheral arterial stiffness (carotid-radial pulse wave velocity),
◊Wave reflection (augmentation index, time to wave reflection), and
Hemodynamics (central blood pressures, pulse pressure amplification).
Key findings of the study:
Upon analysis, the researchers found that women with sleep-disordered breathing (n=41; 23%) had increased carotid-femoral pulse wave velocity across gestation independent of blood pressure and body mass index.
They determined excessive daytime sleepiness as Epworth Sleepiness Score >10. They found that excessive daytime sleepiness was associated with increased carotid-femoral pulse wave velocity only in women with sleep-disordered breathing.
They found that women with mid-gestation (first or second trimester) SDB had an odds of 3.4 for preeclampsia, which increased to an odds of 5.7 for women who also experienced hypersomnolence.
They also found that in women with late gestation (third trimester), sleep-disordered breathing was associated with an 8.2 odds ratio for preeclampsia.
The authors concluded, "High-risk pregnant women with mid-gestational sleep-disordered breathing had greater arterial stiffness throughout gestation compared with those without. Sleep-disordered breathing at any time during pregnancy was also associated with increased preeclampsia risk, and this effect was amplified by hypersomnolence."
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DOI: https://doi.org/10.1016/j.ajog.2021.11.1366