[Circadian rhythm of blood pressure in patients with chronic hypertension and pregnancy].

BACKGROUND

Ambulatory blood pressure monitoring during 24 hours shows a blood pressure variability. The prevalence of chronic hypertension in pregnant women is 1-5%, so it is important to know the changes in blood pressure and cardiovascular risk and prevent complications to the mother and fetus.

OBJECTIVE

To know the circadian rhythm of the blood pressure in the chronic hypertensive pregnant patients, through the ambulatory blood pressure monitoring.

MATERIAL AND METHODS

A cross-sectional and descriptive study included chronic hypertensive pregnant patients, with > 20 weeks of gestation. Assessment of factors related to gynaecologic characteristics, according to the inclusion criteria underwent a washout period of two weeks and they were monitored with a Spacelabs 90207 monitor blood pressure. Quantitative variables by Student t test, one-way ANOVA and Pearson correlation were analysed.

RESULTS

16 chronic hypertensive pregnant patients were included, whose ambulatory blood pressure monitoring for the systolic blood pressure in 24 hours averaged 117.12 ± 5.85 mmHg; 24 hours diastolic blood pressure 71.31 ± 5.89 mmHg; daytime systolic blood pressure 120.18 ± 5.75 mmHg, nocturnal systolic blood pressure 110.31 ± 8.41 mmHg; daytime diastolic blood pressure 75.43 ± 7.32 mmHg, nocturnal diastolic blood pressure 64.25 ± 8.27 mmHg. Significant differences between daytime and night time were found.

CONCLUSION

56% of chronic hypertensive pregnant patients had no nocturnal reduction in systolic blood pressure and 43.75% had no nocturnal changes on diastolic blood pressure. The fact that 50% of patients were non-dippers force us to use long-action antihypertensive therapy and obtain control of the blood pressure for 24 hours.