RESUMO
OBJECTIVES: In the third trimester hypertensive pregnancies, we would like to evaluate effects of white coat hypertension, severity of hypertension and diurnal variation of blood pressure on the fetal outcome by using 24- hour ambulatory blood pressure monitoring. METHODS: Hypertensives(n=50) and normotensives (n=14) in the third trimester of the pregnancy underwent 24-hour ambulatory blood pressure monitoring. We excluded hypertensives(n=5) who became pre-eclampsia patients. Hypertensives(n=45) were classified as white coat hypertensives(n=14, mean ambulatory blood pressure 160 mmHg or diastolic blood pressure >100mmHg) and mild hypertensives(n=26). Sustained hypertensives were also divided into two groups which had diurnal variation of blood pressure or not. To exclude effects of hypertension severity, effects of diurnal variation were evaluated in hypertensives with similar mean arterial blood pressure. Gestational age, body weight, body weight for gestational age were used as parameters of the fetal outcome. RESULTS: 1) The prevalence of white coat hypertension was 28%(14/50). 2) There were no significant differences in the fetal outcome between normotensives(n=14) and white coat hypertensives(n=14). 3) Body weight of fetus and body weight for gestational age in moderate to severe hypertensives(n=5) were less than those of mild hypertensives(n=26), but gestational age was not significantly different between two groups. 4) Body weight of fetus and body weight for gestational age in sustained hypertensives without diurnal variation(n=10) were less than those with diurnal variation(n=8), but gestational age was not significantly different between two groups. 5) All hypertensives who became pre-eclampsia (n=5) were severe hypertensives and had no diurnal variation of blood pressure. CONCLUSION: White coat hypertension in the third trimester was quite often and did not affect on the fetal outcome. The more severe hypertension and/or absence of diurnal variation of blood pressure caused poor fetal outcome. Patients who became pre-eclampsia were severe hypertensives and had no diurnal variation of blood pressure. Ambulatory blood pressure monitoring may have several roles in the antenatal management of hypertenison.