Background: The physiological nature of pregnancy entails substantial alteration in some physiological parameters. There is a dearth of published data concerning the changes in ventilatory function during pregnancy in Nigeria and indeed Africa. Prior knowledge will help tremendously in the management of healthy pregnant women and those with respiratory disorders. Aim and Objectives. To establish some ventilatory function indices in healthy pregnant women in Enugu, South East Nigeria and to determine the effect of gestational age and biophysical parameters on some respiratory function values in normal pregnant women. Subjects and Methods; The work was undertaken in a cross-section of expectant mothers at the antenatal and booking clinics of the one tertiary, one secondary and one primary health care facility in Enugu. A total of 330 participants (250 healthy pregnant and 80 non-pregnant women) were enrolled in the study. Ventilatory functions were determined using a standard Spirometer.