Comparative pulmonary function test parameters in non-tribal and tribal women in singleton first, second, and the third trimester of pregnancy

Background: During pregnancy. women undergo adaptive changes in different organ systems including the respiratory system by hormonal changes and mechanical pressures. Several previous studies reported the change in pulmonary functions in pregnancy and tribal populations. However, trimester-wise, pulmonary functions in tribal women residing in Jharkhand, India, are not available. Aim: This study aimed to find and compare the pulmonary function test parameters in tribal and non-tribal women in singleton first, second, and third trimesters of pregnancy. Methods: We conducted this cross-sectional observational study in a tertiary care hospital in Jharkhand, India, with 58 tribal women and 116 age-matched controls. The pulmonary function tests, namely forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), peak expiratory flow rate (PEFR), maximal mid expiratory flow (MMEF) were measured with a computerized spirometer (Spiro Excel. Medicaid. Punjab, India) and FEV1/FVC was calculated. Results: A total of 58 tribal women with median age 22 (Q1-Q3: 21-25) years and 116 non-tribal women with median age 22 (2025) (P=0.33) participated in the study. The tribal women showed higher respiratory rate (20 [18-24.5] vs. 16 [15-18] per minute, P<.0001), higher MMEF in the first trimester (1.46 [1.12-1.79] vs. 1.24 [1.04-1.5] L/s, P=0.047) and higher PEFR (4.02 [2.78-4.11] vs. 3.15 [2.58-3.87] L/s, P=.047) in the second trimester. There was no difference in the third trimester of pregnancy. In the overall sample, the tribal women showed higher PEFR (3.82 [2.96-4.33] vs. 3.3 [2.73-4.05] L/s. P=.02) and MMEF (1.43 [0.99-1.7] vs. 1.21 [1-1.47] L/s, P=.04). Conclusion: The respiratory rate was higher in the tribal women in the three trimesters of singleton pregnancy compared to the non-tribal women. There was a higher MMEF in the first trimester and PEFR in the second-trimester pregnancy in the tribal women. The finding of this pilot study should he enhanced by further study with a large number of tribal women from this region.