Abstract
Background: Pregnancy is a physiological condition that brings a considerable alteration in hemodynamic activity of the maternal heart. It is very important to understand the cardiac functioning of maternal heart during normal pregnancy because apart from obstetric causes, cardiac disorders are the main cause of mortality in females .Study of electrical activity of the heart is a simple noninvasive and cost effective method which can also raise alarm about the pathological changes in the cardiac function.

Aims & Objective: To study the intervals of Electrocardiogram (ECG) in pregnant women and to compare the same with healthy non pregnant women.

Materials and Methods: A total of 223 females fulfilling the inclusion criteria were recruited for the study. They were divided into four groups - nonpregnant/control group (n=30), 1st trimester (n=36), 2nd trimester (n=64) and 3rd trimester (n= 93). ECG was recorded in lead II. Heart rate, PR, QT interval and QTc were also calculated. These parameters were compared between the groups using one way ANOVA test. A p value of less than 0.05 was considered as significant.

Results: An increase in heart rate and QTc interval and decrease in PR interval was observed in pregnant women when compared with the heart rate of nonpregnant females. This was statistically insignificant when compared between controls and 1st trimester. However a significant change was observed between control group and 2nd/3rd trimester groups. This change was also observed significantly within the pregnant groups when compared with each other.

Conclusion: The cardiovascular hemodynamic adaptation to pregnancy is a well-established physiological fact which was also apparent in this study. Further we noticed a significant change in electrical activity in pregnancy in terms of PR, QT and QTc intervals. These changes became more significant after 1st trimester and peaking during the 3rd trimester.

Key words: Heart Rate; PR Interval; Pregnancy; QTc