author = {Teli, Anita. and Doddamani, Parveen. and Bagali, Shrilaxmi.}, title = {{A study of respiratory rate, tidal volume, inspiratory capacity and inspiratory reserve volume in different trimesters of pregnancy}}, journal ={International Journal of Health & Allied Sciences}, volume ={2}, number ={4}, pages = {294-297}, doi = {10.4103/2278-344X.126766}, year = {2013}, abstract ={Background: The anatomical, physiological and biochemical adaptations in pregnancy are profound. Many of these changes begin soon after fertilization and continue throughout the gestation and changes in the respiratory system are part of the same process. However there is insufficient information regarding the changes in respiratory parameters in different trimesters of pregnancy. Aims: The aim of the study was designed to evaluate the pulmonary function tests in 1 st , 2 nd and 3 rd trimesters of pregnancy and compare them with non-pregnant control group. Materials and Methods: A cross-sectional study was carried in 200 healthy women in the age range of 19-35 years. The subjects were distributed in four groups, as control (non-pregnant) group and 1 st , 2 nd and 3 rd trimester pregnant groups. Number of subjects in each group was 50. Respiratory parameters in control and study groups were recorded. Statistical Analysis: By 'Z ' test. Results: There was gradual significant increase in respiratory rate in all trimesters of pregnancy. There was a gradual decrease in tidal volume in 1 st , 2 nd and 3 rd trimesters of pregnancy when compared to non pregnant women. There was significant decrease in Inspiratory Reserve Volume and Inspiratory Capacity. Conclusion: The changes in pulmonary function are attributed to major adaptations in the maternal respiratory system and are influenced by the mechanical pressure of enlarging gravid uterus, elevating the diaphragm and restricting the movements of lungs thus hampering the forceful expiration and also might be due to decline in alveolar Pco 2 caused by hyperventilation which acts as bronchoconstrictor; in addition to sensitization of respiratory center due to progesterone}, URL ={https://www.ijhas.in/article.asp?issn=2278-344X;year=2013;volume=2;issue=4;spage=294;epage=297;aulast=Teli;t=6}, eprint ={https://www.ijhas.in/article.asp?issn=2278-344X;year=2013;volume=2;issue=4;spage=294;epage=297;aulast=Teli;t=6} }