Introduction: The physiological changes during pregnancy facilitate the adaptation of the cardiovascular system to the increased metabolic needs of the mother enabling adequate delivery of oxygenated blood to the peripheral tissues and to the fetus. The present study was designed to compare the cardiovascular changes at different trimesters of pregnancy with the nonpregnant women.

Materials and Methods: It is a cross sectional study conducted in the Department of Physiology after institutional clearance and consent from all the participants,150 pregnant women in the age group of 20-35yrs who were attending the OPD of OBG were recruited and divided into 3 subgroups comprising 50 women in first, second and third trimesters of pregnancy. The control group was comprising of another apparently healthy age matched 50 non-pregnant women. The anthropometric, Blood pressure and ECG were recordedduring morning hours.

Statistical Analysis: The data were expressed as Mean±SD. Z test was used for comparison between control and study groups andwithin the study group. ‘p’ value of 0.05 or less was considered as statistically significant.

Result: There was a significant increase in the pulse rate of the subjects in the 1st, 2nd and 3rd trimesters of pregnancy when compared to the control group (p=0.0001) and a significant decrease in SBP in the 1st and 2nd trimester of pregnancy compared to control group (p=0.0146 and 0.0001 respectively). The MAP was significantly decreased in the 2nd trimester of pregnancy compared to control group (p=0.0003) whereas, the decline was insignificant 1st and 3rd trimesters of pregnancy (p=0.596 and 0.638 respectively).

Discussion: The pregnancy induced changes in the cardiovascular system develop primarily to meet the increased metabolic demands of mother &
fetus. The overall decrease in vascular tone in response to an unknown endocrine stimulus represents the very first adaptive change in cardiovascular system giving rise to both an increased vascular capacity and a decreased filling state.

Keywords: Pregnancy; BP Responses; ECG Changes; Trimesters.