Open AccessObjective : Pregnancy is characterized by profound changes in the function of virtually every regulatory system in the human body. The events in pregnancy elicit one of the best examples of selective anatomical, physiological & biochemical adaptation that occur during pregnancy & profound changes in respiratory physiology is a part of the same process. Thus this study was designed to evaluate the pulmonary function tests in 1st, 2nd and 3rd trimesters of pregnancy & compare them with non-pregnant control group.
Method : 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, i.e control (non-pregnant) group and 1st , 2nd &3rd trimester pregnant groups. Number of subjects in each group is 50. We recorded respiratory parameters in control and study groups. Statistical analysis done by ‘Z’ test.
Result: There was significant decrease in FVC, PEFR & MEP in all trimesters of pregnancy with maximum decrease of FVC in 1st trimester &Â PEFR, MEP in 2nd trimester.
Conclusion: The changes in pulmonary function are attributed to major adaptations in the maternal respiratory system & are also be influenced by the mechanical pressure of enlarging gravid uterus, elevating the diaphragm & restricting the movements of lungs thus hampering the forceful expiration & decrease in 1st trimester might be due to decline in alveolar Pco2 caused by hyperventilation which acts as bronchoconstrictor & due to sensitization of respiratory centre due to progesterone.