Introduction: During pregnancy various changes occurs in sympathetic and parasympathetic functions in pregnant woman. Sometime these changes may be beneficial for pregnant woman or sometimes these changes may create health problems. But most important thing is in pregnant woman the normal values for these parameters may altered as compare to non-pregnant woman and must be thoroughly evaluated before therapeutic intervention. These changes are initiated by various hormonal changes during pregnancy and also due to mechanical pressure exerted by growing fetus during pregnancy.Study of parasym pathetic functions during pregnancy help to predict any pre-existing autonomic dysfunction. Objective: To study one of the parasympathetic function test i.e immediate heart rate response to standing also known as 30:15 ratio in pregnant woman from rural population of India. Methods: A case control observational study was carried out in the department of Physiology in collaboration with Obstetrics and Gynecology department at Rural Medical College Loni. Total four hundred eighty subjects selected for study. Subjects were divided in to one hundred twenty non-pregnant and one hundred twenty pregnant women in each trimester of pregnancy. Imme diate heart rate response to standing was studied on __ampersandsignldquo;CANWIN- Cardiac Autonomic Neuropathy Analyzer__ampersandsignrdquo;. Data was analyzed using ANOVA test and multiple comparison analysis. Results: A significant decrease in immediate heart rate response to standing (p __ampersandsignlt; 0.05) observed in pregnant women as com pared to non-pregnant women. Conclusion: The study showed a significant decrease in immediate heart response to standing in normal pregnant women as compared to non-pregnant women from the rural population of India. A study of parasympathetic functions must be done to predict any pre-existing autonomic dysfunction during pregnancy.