Central aortic blood pressure and augmentation index during normal pregnancy

The current study tested the hypothesis that pregnancy-related changes are more pronounced in central hemodynamics, and both central aortic systolic blood pressure (cSBP) and augmentation index (AIx) are independent from brachial systolic blood pressure (bSBP) in normal pregnant subjects. In 830 healthy pregnant women from 12 to 36 weeks gestation, we measured cSBP and AIx-75 (AIx at heart rate of 75 beats per minute) non-invasively by pulse waveforms of the radial artery using an automated applanation tonometric system. In 69 pregnant women, we recorded these data longitudinally. cSBP and AIx-75 significantly declined during pregnancy, reaching its nadir in mid-pregnancy and rising towards term. Pregnancy-related changes were more pronounced in AIx-75 compared with cSBP, but less evident in bSBP. AIx-75, but not cSBP, was independent from bSBP throughout pregnancy. cSBP and AIx-75, but not bSBP, were significantly increased in healthy pregnant women older than 35 years. This study established normal values for pulse wave analysis parameters throughout pregnancy, and indicated that pulse wave analysis might offer additional and independent information about maternal arterial compliance to conventional brachial blood pressure measurements. These data may be used as the basis for further investigation into the role of pulse wave analysis in the assessment, management and prediction of disorders, which might interfere with pregnancy-related cardiovascular adaptations.