title: Risk factors for sleep-disordered breathing in pregnancy.
abstract: BACKGROUND
  Symptoms of sleep-disordered breathing (SDB) are common among pregnant women, and several studies link SDB symptoms with gestational hypertension and preeclampsia. However, few prospective studies objectively measuring SDB during pregnancy have been performed.
  
  
  OBJECTIVE
  We performed a prospective cohort study examining risk factors for third trimester SDB in pregnant women.
  
  
  METHODS
  105 pregnant women from the Hospital of the University of Pennsylvania obstetrics practices completed first and third trimester overnight polysomnography studies. We examined whether the number of SDB events per hour of sleep increased during pregnancy. We performed unadjusted and multivariable logistic regression analyses to estimate the effects of usual and pregnancy-specific characteristics on development of third trimester obstructive sleep apnoea (OSA). In secondary analyses, we examined the relationship between objectively measured SDB, hypertensive disorders of pregnancy, and other adverse maternal-fetal outcomes.
  
  
  RESULTS
  Mean Apnoea-Hypopnoea Index increased from 2.07 (SD 3.01) events/h at baseline (first trimester) to 3.74 (SD 5.97) in the third trimester (p=0.009). 10.5% of women had OSA in the first trimester. By the third trimester, 26.7% of women had OSA. In multivariable analyses, first trimester body mass index (BMI) and maternal age were significantly associated with third trimester OSA.
  
  
  CONCLUSIONS
  Third trimester OSA is common. Risk factors for third trimester OSA among women without baseline SDB include higher baseline BMI and maternal age.
authors.affiliation: Center for Sleep and Circadian Neurobiology, University of Pennsylvania School of Medicine, , Philadelphia, Pennsylvania, USA.
authors.forename: Grace W
authors.initials: GW
authors.lastname: Pien
authors.forename: Allan I
authors.initials: AI
authors.lastname: Pack
authors.forename: Nicholas
authors.initials: N
authors.lastname: Jackson
authors.forename: Greg
authors.initials: G
authors.lastname: Maislin
authors.forename: George A
authors.initials: GA
authors.lastname: Macones
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schwab
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D010414:Pennsylvania; D017286:Polysomnography; D011247:Pregnancy; D011248:Pregnancy Complications; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult
keywords: Sleep Apnoea