Closing volume in normal pregnancy

Abstract

Closing volume and other principal lung volumes were measured during and after pregnancy in 10 healthy non-smoking women aged 18-24 yr. There were no significant changes in closing volume or closing capacity. A decrease in functional residual capacity as pregnancy progressed resulted in airway closure during tidal breathing in more than 50% of subjects at term when in a supine position, but this did not occur when they were seated. © 1981 Macmillan Publishers Ltd.