title: Hypertension, snoring, and obstructive sleep apnoea during pregnancy: a cohort study.
abstract: OBJECTIVE
  To assess the frequency of obstructive sleep apnoea among women with and without hypertensive disorders of pregnancy.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Obstetric clinics at an academic medical centre.
  
  
  METHODS
  Pregnant women with hypertensive disorders (chronic hypertension, gestational hypertension, or pre-eclampsia) and women who were normotensive.
  
  
  METHODS
  Women completed a questionnaire about habitual snoring and underwent overnight ambulatory polysomnography.
  
  
  METHODS
  The presence and severity of obstructive sleep apnoea.
  
  
  RESULTS
  Obstructive sleep apnoea was found among 21 of 51 women with hypertensive disorders (41%), but in only three of 16 women who were normotensive (19%, chi-square test, P=0.005). [Author correction added on 16 June 2014, after first online publication: Results mentioned in the abstract were amended.] Non-snoring women with hypertensive disorders typically had mild obstructive sleep apnoea, but >25% of snoring women with hypertensive disorders had moderate to severe obstructive sleep apnoea. Among women with hypertensive disorders, the mean apnoea/hypopnoea index was substantially higher in snorers than in non-snorers (19.9±34.1 versus 3.4±3.1, P=0.013), and the oxyhaemoglobin saturation nadir was significantly lower (86.4±6.6 versus 90.2±3.5, P=0.021). Among women with hypertensive disorders, after stratification by obesity, the pooled relative risk for obstructive sleep apnoea in snoring women with hypertension compared with non-snoring women with hypertension was 2.0 (95% CI 1.4-2.8).
  
  
  CONCLUSIONS
  Pregnant women with hypertension are at high risk for unrecognised obstructive sleep apnoea. Although longitudinal and intervention studies are urgently needed, given the known relationship between obstructive sleep apnoea and hypertension in the general population, it would seem pertinent that hypertensive pregnant women who snore should be tested for obstructive sleep apnoea, a condition believed to cause or promote hypertension.
authors.affiliation: Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, MI, USA; Department of Obstetrics & Gynecology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: O'Brien
authors.forename: A S
authors.initials: AS
authors.lastname: Bullough
authors.forename: M C
authors.initials: MC
authors.lastname: Chames
authors.forename: A V
authors.initials: AV
authors.lastname: Shelgikar
authors.forename: R
authors.initials: R
authors.lastname: Armitage
authors.forename: C
authors.initials: C
authors.lastname: Guilleminualt
authors.forename: C E
authors.initials: CE
authors.lastname: Sullivan
authors.forename: T R B
authors.initials: TR
authors.lastname: Johnson
authors.forename: R D
authors.initials: RD
authors.lastname: Chervin
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology*; D017286:Polysomnography; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology*; D012913:Snoring / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Hypertension; obstructive sleep apnoea; pregnancy; snoring