Predictable time structure of circadian cardiovascular characteristics in healthy human pregnancy

Conventional time-unspecified single measurements of blood pressure (BP) and heart rate (HR) may be misleading since they may be influenced, among other factors, by the patient´s emotional state, position, diet, and external stimuli. The evaluation of predictable variability in BP and HR by the use of fully ambulatory devices, and the proper processing of the time series thus obtained, can be useful in assessing early cardiovascular disease risk in pregnancy. The authors have used this approach to quantify changes in 24-hour synchronized (circadian) characteristics of BP and HR in two consecutive pregnancies of a clinically healthy woman. The results were then compared with those obtained from data sampled after the second pregnancy. BP and HR were automatically monitored, at 1-hr intervals, each time for at least 48-hrs and for a total of 76 days of monitoring in each pregnancy