Study of blood pressure (BP) changes during pregnancy is essential for understanding the complications of pregnancy like birth defects, gestational diabetes, pre-eclampsia, bleeding disorders etc. Determinants of blood pressure systolic blood pressure (SBP), diastolic blood pressure (DBP) influenced by the pre-pregnancy body mass index (BMI) and its values gradually change during all the three trimesters. At present, little is known about the association of BP parameters with different grades of BMI in all the trimesters of pregnancy so our objective of this study was to elucidate the aforesaid relationship. We selected 200 pregnant women from antenatal clinics of obstetrics & gynaecology, J.N. Medical College, A.M.U., Aligarh. Pre-pregnancy body mass index (BMI) was calculated by using Quetlet’s Index. On the basis of BMI, all participants were divided into three groups: underweight, normal, overweight. Reading of blood pressure of participating women was taken by using a standard mercury sphygmomanometer in each of the three trimesters. Mean values were calculated and compared between different BMI groups in all the trimesters and of pregnancy. The statistical software SPSS (version 16) was used for data analysis and unpaired t- test was applied. SBP, DBP of underweight and overweight pregnant women were not significantly decreased from first to second trimester and were not significantly increased from second to third trimester. In pregnant women of normal weight, there was a significant fall in SBP, DBP in mid pregnancy followed by which further increase up to the third trimester. The no significant fall in BP parameters in underweight and overweight pregnant women in mid pregnancy was related to the increase in the risk of development of preeclampsia. The cause of pre-eclampsia may be explained by the mechanism involved in endothelial dysfunction which will be discussed later on. We found that the level of risk for complications of pregnancy is increased with abnormal BP parameter patterns in pregnant women having different BMI; thus, women with unhealthy weight should be offered preconception counseling, nutritional consultation, exercise program, and careful screening of obstetrics complications during pregnancy.

Key Words: Pregnancy; BP monitoring; Pre-eclampsia; BMI.