Abstract Background: The physiological adaptations of the pregnant woman involve the circulatory, respiratory, digestive, renal, endocrine and metabolic systems. Their precise knowledge allows the clinician to verify the extent of the adaptation in pregnant women and helps to avoid unnecessary treatment of physiological changes misinterpreted as pathological changes in reference to prepregnancy standards. We designed the study to understand changes in pulmonary function tests during advanced pregnancy. Result: Mean value of PEFR (% of predicted) is decreased significantly in study group as compared with control group (P=0.001) Conclusion: It is concluded that pulmonary function test like PEFR decreases due to gravid state in advanced Pregnancy.

Keywords: Body Mass Index, Systolic Blood Pressure, Diastolic Blood Pressure, Pulmonary Function Test, Peak Expiratory Flow Rate.