The New Indian Journal of OBGYN. 12(1):136-140

A comparative study of heart rate variability in pregnant and nonpregnant women in a tertiary care hospital of East India

Shahin Bano, Dharmendra Kumar, Malti Kumari

ABSTRACT

Background: Pregnancy is associated with dramatic cardiovascular adaptations, including increases in heart rate and blood volume, resulting in increased cardiac output throughout pregnancy and in decreased systemic vascular resistance in the first half of pregnancy with subsequent attenuation in the last trimester. The evidence of association between these cardiovascular parameters is well established but the evidence on extent of association needs to be strengthened with more research. Objectives: The study aims to evaluate changes in heart rate during deep breathing and to compare the changes in heart rate variability at various phases of pregnancy in different age groups. Materials and methods: Hospital based observational and prospective study was done from January 2018 to June 2019. Heart rate variability was determined by the method given by Wheeler and Watkins in which heart rate maximum and minimum was determined during deep inspiration and expiration. Heart rate variability was considered as the difference between maximum and minimum heart rate. The difference in data between two groups was analysed by using unpaired t test and the difference in interphase data within same group was analysed using repeated measure one way ANOVA. Results: There was higher heart rate but lower heart rate variability in pregnant women as compared to nonpregnant women. Heart rate variability was significantly lower in pregnant women of above 30 years (p<0.05). In the present study the mean of heart rate variability of pregnant women in second trimester was 5.96 and the mean of heart rate variability of non pregnant women was 11.52. Our study shows that the heart rate variability in pregnant women is significantly lower as compared to non pregnant women (p<0.05). Conclusion: We have found significant association of high heart rate and low heart rate variability with pregnancy and this association was stronger in second trimester of pregnancy. Moreover, the feasibility of predicting clinical outcomes in pregnancy by measuring heart rate variability bears further investigation.