Women with high-risk pregnancies who experience sleep-disordered breathing have an increased risk for preeclampsia, according to a study published in the American Journal of Obstetrics & Gynecology.

The prospective observational cohort study involved women with high-risk singleton pregnancies, author Stella S. Daskalopoulou, MD, MSc, PhD, of the department of medicine’s division of internal medicine at McGill University Health Centre in Montreal, and colleagues reported in the study.

High-risk factors included age of at least 35 years, BMI of at least 25 kg/m², chronic hypertension, pre-existing diabetes or renal disease, conception via in vitro fertilization and personal or first-degree relative family history of preeclampsia.

Of the 235 women recruited between 10 and 13 weeks of gestation at two tertiary obstetric clinics in Montreal, 181 women completed questionnaires about their sleep based on the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index and restless legs syndrome during each trimester.

Women identified with sleep disordered breathing (SDB), defined as three or more incidences of loud snoring or witnessed apneas each week, in the first or second trimester were diagnosed with mid-gestation SDB. Women identified with SDB in the third trimester were diagnosed with late-gestation SDB.

The researchers also conducted arterial stiffness, wave reflection and hemodynamic assessments between 10 and 13 weeks and again six more times at approximately 4-week intervals through the rest of the pregnancy.

Carotid-femoral pulse wave velocity (cfPWV), which is considered the gold standard for predicting arterial stiffness and is predictive of preeclampsia, and carotid-radial PWV were calculated to determine aortic and peripheral arterial stiffness, respectively.

According to the study, the 41 women (23%) who had SDB also had increased cfPWV across gestation independent of blood pressure and BMI (P = .042). Also, only women with SDB saw an association between excessive daytime sleepiness and increased cfPWV.

After 20 weeks’ gestation, women who had BP of at least 140 mm Hg/90 mm Hg were diagnosed with preeclampsia.

Women with mid-gestation SDB had an OR of 3.4 (95% CI, 0.9-12.9; P = .063) for preeclampsia, which increased to an OR of 5.7 (95% CI, 1.1-26; P = .028) for women who also experienced hypersomnolence. Women with late-gestation SDB had an OR of 8.2 (95% CI, 1.5-39.5; P = .009) for preeclampsia.

Additionally, the researchers reported a positive association between excessive daytime sleepiness and central arterial stiffness in women with SDB but not in women who did not have SDB. Women who reported SDB and excessive daytime sleepiness appeared to have a greater risk for preeclampsia than women with SDB alone as well.

However, women who had positive restless legs syndrome scores did not see increased odds for developing preeclampsia either in mid-gestation (OR = 1.23; 95% CI, 0.25-4.68) or late gestation (OR = 1.01; 95% CI, 0.21-3.75). The same held true for women who had positive Pittsburgh Sleep Quality Index scores in mid-gestation (OR = 2.11; 95% CI, 0.58-8.66) or late gestation (OR = 2.83; 95% CI, 0.65-19.81).

Overall, the researchers said, there was an association between SDB in the first or second trimester and greater central arterial stiffness starting at 10 to 13 weeks’ gestation for women with high-risk pregnancies.

Further, the researchers said, their results provide supporting evidence for arterial stiffness as an important mediator and promising surrogate endpoint for vascular dysfunction in preeclampsia, as well as for the need to screen for SDB throughout pregnancy.