Pulmonary function test in the three trimesters of pregnancy of primigravid women in Benin-City

Abstract

The advancing pregnancy of the primigravid pregnant women may have negative effect on lung function because of the presumably naïve compliance of the anterior abdominal. This study measured lung function such as; Forced Vital Capacity (FVC), Forced Expiratory Volume in One Second (FEV1) and FEV1/FVC ratio in the three trimesters of primigravid pregnancy. A total of 15 healthy volunteers who were attending Ante-natal clinic at the St Philomena catholic hospital were studied longitudinally. Lung function test was measured using a spirometer on the 12^th week, 24^th week and 36^th week as first trimester, second trimester and third trimester respectively. The control subjects (n=15) were apparently healthy volunteers from the St Philomena School of Midwifery. The forced vital capacity in the first, second and third trimesters of pregnancy were 3.26 ± 0.26L; 3.75± 0.30L and 3.25 ± 0.28L respectively and they were not statistically different (p > 0.05) from the non-pregnant control (3.21 ± 0.35L). However, the FEV₁ in the second trimester (3.75± 0.30L) was significantly higher (p < 0.05) than the control value of 2.62 ± 0.11L. The FEV₁/FVC ratio in the second trimester pregnancy (82.90 ± 0.49%) was significantly higher (p < 0.05) than the control value of 81.60 ± 0.30%, FEV₁/FVC ratio in the third trimester pregnancy (80.00 ± 0.36%) was significantly lower (p < 0.05) than the control value. The lung functions measured in the three trimesters of pregnancy were within normal range but optimal homeostasis was observed in the second trimester of pregnancy.

Keywords: Pregnancy, Trimester, FVC, FEV₁, FEV/FVC ratio