title: Changes in pulmonary function during pregnancy: a longitudinal cohort study.
abstract: OBJECTIVE
  To record any physiological changes in lung function during healthy pregnancies, and evaluate the influence of parity, pregestational overweight, and excessive weight gain.
  
  
  METHODS
  Longitudinal cohort study.
  
  
  METHODS
  Antenatal clinic at Oslo University Hospital.
  
  
  METHODS
  One hundred healthy white women with singleton pregnancies.
  
  
  METHODS
  The women were studied with repeated measures of lung function using spirometry at a gestational age of 14-16, 22-24, 30-32, and 36 weeks, and at 6 months postpartum.
  
  
  METHODS
  Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF), also expressed as a percentage of predicted values according to age and height: i.e. FVC%, FEV1%, and PEF%.
  
  
  RESULTS
  Both FVC and FVC% increased significantly after 14-16 weeks of gestation (P=0.001), as was the case for both PEF and PEF% (P<0.001). FVC, FVC%, PEF, and PEF% in early and mid-pregnancy were significantly lower compared with the postpartum value (all P<0.05). Nulliparous women had an overall 4.4% lower value of FVC% than parous women (P=0.039). There were no differences in FVC, FEV1, or PEF dependent upon pregestational overweight or excessive weight gain.
  
  
  CONCLUSIONS
  Forced vital capacity (FVC) increases significantly after 14-16 weeks of gestation. The FVC% is significantly higher in parous compared with primigravida women, suggesting that the changes in FVC occurring during pregnancy persist postpartum. PEF increases significantly during healthy pregnancies, and should be interpreted cautiously in pregnant women with impaired lung function.
authors: Department of Anaesthesiology, Division of Critical Care, Oslo University Hospital, Rikshospitalet, and Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway. Guro.Grindheim@oslo-universitetssykehus.no
authors: G
authors: G
authors: Grindheim
authors: K
authors: K
authors: Toska
authors: M-E
authors: ME
authors: Estensen
authors: L A
authors: LA
authors: Rosseland
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000502:physiology*; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D049590:Postpartum Period / Q000502:physiology; D011247:Pregnancy / Q000502:physiology*; D011256:Pregnancy Outcome; D011264:Pregnancy Trimesters / Q000502:physiology; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult