Previous studies of obstructive sleep apnea (OSA) risk in gravidas with chronic hypertension (cHTN) did not control for obesity as a risk factor for OSA. We therefore performed this study to evaluate whether OSA is more prevalent among gravidas with cHTN compared to normotensive gravidas matched for body mass index (BMI) and gestational age (primary outcome). We also assessed whether OSA is more severe when comorbid with cHTN in pregnancy (secondary outcome).
This was a single-center, prospective cohort study. Adult gravidas at 10–20 weeks of gestation, with and without cHTN, were enrolled and BMI matched. All subjects answered OSA screening questionnaires and underwent a home sleep test when they were between 10 and 20 weeks of gestation. Pregnancy outcomes were followed for all subjects. We performed univariable and multivariable logistic regression to model the relationship between cHTN status and OSA.
A total of 100 pregnant subjects (50 with cHTN and 50 normotensive) completed a home sleep test of 2 hours or more. There were no differences in demographic variables between the 2 groups, except that gravidas with cHTN were significantly older than normotensive subjects (mean ± standard deviation [SD] 34 ± 4 vs 30 ± 6 years; P < .001). OSA was more prevalent (64% vs 38%; P = .009; odds ratio [95% confidence interval (CI)] 2.90 [1.30–6.65]; P = .01) and more severe in gravidas with cHTN (moderate or severe OSA 59% vs 21%; P = .009). After controlling for age, we found no overall association between cHTN on OSA risk (adjusted odds ratio [95% CI] 2.22 [0.92–5.40]; P = .076). However, among gravidas older than 25 years of age, cHTN was associated with higher odds of OSA (adjusted odds ratio [95% CI], 2.64 [1.06–6.71], P = .038).
cHTN and age are important risk factors for OSA in gravidas. Gravidas with cHTN should be screened for OSA in early pregnancy. Future studies may validate screening tools that include cHTN and age, and investigate the role of OSA therapy in blood pressure control.