A comparison between conventional and 24-hour automatic blood pressure monitoring in hypertensive pregnancy.

OBJECTIVE

To map the conformity between 24-hour and conventional blood pressure (BP) monitoring (24BPM, CBPM) in pregnancy.

STUDY DESIGN

Prospective comparative.

MATERIAL AND METHODS

A standardized single BP measurement and parallel 24BPM and CBPM were carried out in 99 women (125 recordings) hospitalized for hypertension.

RESULTS

Except for BP oscillation amplitude, corresponding variables correlated significantly between the methods. The mean systolic BP (SBP) was significantly higher with 24BPM compared with both CBPM (3.1 mmHg) and with the single BP measurement (4.6 mmHg). The mean diastolic BP (DBP) was significantly lower with 24BPM compared with CBPM (2.4 mmHg) and with the single measurement (2.7 mmHg). If a cut-off at 140/90 mmHg had been used for the diagnosis of hypertension and with 24BPM as the golden standard, a false positive/negative diagnosis would have resulted in 35%/20% of cases with the single BP measurement, and in 24%/17% with CBPM.

CONCLUSIONS

24BPM and CBPM gave significantly correlated but different values of the BP. The differences were small in terms of absolute mm Hg values, but resulted in a high rate of false positive and false negative diagnoses of hypertension. 24BPM cannot substitute the traditional methods for BP monitoring in pregnancy unless a new definition of hypertension is established.