Electrocardiographic Changes during the Third Trimester of Pregnancy: A Cross Sectional Study

This study is intended to evaluate the changes in Electrocardiogram (ECG) in the third trimester of pregnancy. The cross sectional study was conducted on two hundred subjects whose age ranged between 18 and 35 years. One hundred pregnant women and one hundred non-pregnant women attending the Government General Hospital in Kakinada, Andhra Pradesh were included. The 12 lead ECGs of the participants were taken in supine position. The ECGs were studied for different parameters like heart rate PR, QT intervals, T wave, PR, QT segments, atrial and ventricular depolarization axis. QTc interval was calculated using Bazett’s formula. The results were analyzed using student’s t-test and probability (p value) was calculated. The results showed increase in heart rate in pregnant women compared to the control group. The decrease in PR interval associated with pregnancy was highly significant. The analysis showed statistically significant increase in QT and QTC interval (p value 0.003, 0.0001). The QRS frontal axis compared to control showed increased tendency to shift towards left with advancing pregnancy. QRS Frontal axis showed a statistically significant decrease in the 3rd trimester (p value 0.001). This study shows that changes in ECGs in the third trimester pregnant women do occur. Therefore interpretation and evaluation of electrocardiograms in pregnancy should be done with due caution.