Study of Forced Expiratory Volume in First Second (FEV1) and Ratio of Forced Expiratory Volume in First Second and Forced Vital Capacity in Percentage (FEV1/FVC%) in Pregnant Women

Abstract

Background: A few data are available on the effects of pregnancy on pulmonary function in different countries. But no such established data are available in our country. So we designed this study in our population. Objectives: To observe the forced expiratory volume in first second (FEV1) and ratio of forced expiratory volume in first second and forced vital capacity (FEV1/FVC%) in different trimesters of normal pregnant women and to compare them with those of healthy non-pregnant women. Materials and Methods: This observational and analytical study was carried out in the department of Physiology, Dhaka Medical College during July 2004 to June 2005. Total 100 women aged from 25 to 35 years without any recent history of respiratory tract diseases were selected as study population. Among them, 75 normal pregnant women were taken as experimental and 25 healthy non-pregnant women were taken as control groups. The experimental group included 25 pregnant women in first trimester, 25 in second trimester and 25 in third trimester. Forced expiratory volume in first second (FEV1), ratio of percentage of forced expiratory volume in first second and forced vital capacity (FEV1/FVC%) were measured in pregnant and non-pregnant control women. The FEV1 and FEV1/FVC% were measured by using an ‘automatic spirometer’. Statistical analyses were done by unpaired Student’s ‘t’ test between the study groups and p value <0.05 was taken as significant.Results: The mean ± SD of measured values of FEV1 were 2.41 ± 0.87, 2.28 ± 0.59, 2.15 ± 0.74 and 1.89 ± 0.76 liters in non-pregnant women and in pregnant women during first trimester, second trimester and third trimester. The mean ± SD of measured values of FEV1/FVC% were 75.22 ± 16.77, 74.86 ± 11.06, 74.42 ± 17.43 and 71.81 ± 15.87% in nonpregnant women and in pregnant women during first trimester, second trimester and third trimester. Conclusion: The FEV1 and FEV1/FVC% were significantly lower in third trimester pregnant women than that of non-pregnant and first trimester of pregnant women and FEV1/FVC% gradually decreased from first to third trimester of pregnant women. DOI: http://dx.doi.org/10.3329/jemc.v2i1.11926 J Enam Med Col 2012; 2(1): 29-32