Assessment of maternal vascular stiffness indices in three trimesters of normal pregnancy.

ABSTRACT

Normal pregnancy is associated with intense alterations in the maternal cardiovascular system. The aim of the present study was, to assess the influence of normal pregnancy on maternal central aortic pressures, arterial stiffness, and arterial wave reflection using non-invasive PC based cardiovascular risk analysis system (PeriscopeTM). The current study was conducted on 137 women with, normotensive, healthy, singleton pregnancies at first trimester (n=42), second trimester (n=48), third trimester (n=47) of pregnancy and 35 age matched non-pregnant controls. There was no significant correlation between the estimated means for age and systolic and diastolic blood pressure. There was progressive and significant increase in BMI as pregnancy progresses (p=0.0001). Heart rate rose significantly from Pre-pregnant to second and second to third trimesters (P<0.003). There were no significant changes observed in central aortic diastolic pressure (AoDiaBP) as pregnancy progressed (p=0.235) however Post Hoc comparisons showed a significant increase in central aortic systolic blood pressure (AoSysBP) and central aortic pulse pressure (AoPP) during first trimester when compared with non pregnant control group (p=0.039 and 0.048 respectively). There was significant increase in central aortic augmentation pressure (AoAugP) in first trimester compared to non pregnant control group (p=0.024). All the parameters of central aortic pressures were increased in the first trimester but decreased in the second trimester and again increased in the third trimester of pregnancy. There was a significant drop in Brachial-Ankle Pulse wave Velocity (baPWV) during first trimester of pregnancy compared to non-pregnant control group (p=0.0001) after that there is a progressive increase in baPWV in second and third trimester of pregnancy. In the third trimester baPWV is increased to more than non-pregnant control group but it was non significant (p=0.562) however it was significantly higher than first trimester (p=0.0001). Carotid-femoral Pulse wave velocity (cfPWV) also followed the same sequence as BaPWV but the drop in cfPWV during first trimester was not significant (P=0.135). All of the variables of hemodynamic and arterial compliance differed between participants with various trimester of pregnancy and non-pregnant control group. A significant up and down changes in Augmentation index (Aix) was observed from control to first, second and third trimester of pregnancy (3.14 to 6.74 to 2.63 to 10.51 respectively, P<0.0001). To summarize our report show that normal pregnancy is associated with a significant cardiovascular adaptation indicated by alteration in central aortic blood pressure, augmentation index and pulse wave velocity.