Changes in pulmonary function during pregnancy: a longitudinal cohort study

Please cite this paper as: Grindheim G, Toska K, Estensen M, Rosseland L. Changes in pulmonary function during pregnancy: a longitudinal cohort study. BJOG 2012;119:94–101. Objective To record any physiological changes in lung function during healthy pregnancies, and evaluate the influence of parity, pregestational overweight, and excessive weight gain. Design Longitudinal cohort study. Setting Antenatal clinic at Oslo University Hospital. Population 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. Main outcome measures 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