Ambulatory Blood Pressure Mornitory In Gestational Hypertension

Gestational hypertension is an unique disease in pregnancy which threatens the health of pregnant women and fetus seriously.Hypertension and albuminuria are its main clinical symptoms.It is also the primary cause that lead pregnant women and perinatal fetus to death.Especially eclampsia which induced by gestational hypertension impairs lives of pregnant women and fetus severely.So it is very important to control blood pressure(BP) for hyertensive women.At present the diagnosis of gestational hypertension still relies on casual blood pressure(CBP) measurement.However,these clinical BP values provide only a measurement that represents only a fraction of the 24-hour BP profile,they are easily influenced by many factors,such as physical activities,the state of emotions and so on. Therefore,this kind of measurement has certain limitations.Ambulatory blood pressure mornitory(ABPM) can overcome the problems associated with clinical BP measurement,and reflect circadian rhythm of blood pressure.Presently ABPM has been widely used in cardiovascular diseases,while it is still in the primary stage of diagnosis and treatment of gestational hypertension.Objective:to study the use of ABPM in gestational hypertension1.To study the characteristics of 24-hour ambulatory blood pressure of normotensive pregnant women2.To study the characteristics of 24-hour ambulatory blood pressure of pregnant women with gestational hypertension3.To study the correlation between ABP and renal damage4.To study the correlation between ABP and fetal weight Methods1.Subject:We studied 76 untreated pregnant women(two groups:42 nomotensive,34 with gestational hypertension) who received obstetric care at the Obstetric Department of the First Afflicated Hospital of Anhui Medical University during the period from November,2006 to July,2007.2.Methods:2.1 ABPM:Each woman was measured by ambulatory blood pressure mornitores(mobile-O-graph,made in German) every 30 minutes during 24 hours.And we devided 24 hours into two parts:the day(6:00～21:59) and the night(22:00～05:59).All subjects were told to keep their daily activities during sampling pieriod.Women with gestational hypertension took ABPM before treatments.2.2 CBP:All subjects measured CBP before they take ABPM.2.3 Laboratory examination:All subjects took examinations,such as blood routine test,liver function,renal function,clotting function and so on,while they took ABPM.3.Statistical analysis:All data were analysed on SPSS 10.0 software or SAS 7.0 software.The quantitative variables were compared by t-test,while the qualitative variables were compared by Chi-square test(x~2 test).And the results of laboratory examinationes were analysized by multiple linear regression,pearson or spearman correlation.Results1.Compared with normotensive pregnancies,a significant elevation of all parameters obtained from ABPM was found in pregnancies with gestational hypertension(P＜0.01)2.For normotensive women,the profile of circadian rhythm in BP presented a shape of "dipper".For women who developed gestational hypertension or preeclampsia,blood pressure varied at high level of BP,which had lost circadian rhythm of "dipper".24-hour heart rates of two groups all presented the shape of "dipper",which suggested BP and heartrate was not synchronous.3.The characteristics of 24-hour ambulatory blood pressure of pregnant women with hypertension.3.1 Circadian arrhythm of BP:Comparing circadian rhythm,we find a statistically significant difference between the two groups(P＜0.01).The characteristic of circadian rhythm in pregnant women with gestational hypertension was "non-dipper" and "anti-dipper",while normotensive pregnancies manifested it as "dipper" and "non-dipper"3.2 Nocturnal hypertension:Nomatter what it was SBPor DBP,the BP load index in day was lower obviously than that in night(P＜0.001).It indicated the elevation of SBP and DBP during night characterized BP of pregnancies with gestational hypertension.3.3 For hypertensive women,,BPVI of DBP were higher than that of normotensive women.There were 5 cases that only diurnal DBP elevated,2 women that only diurnal SBP elevated,5 that only noctural DBP elevated,1 that only noctural SBP elevated.It suggested the elevation of DBP characterized BP of pregnant women with hypertension.4.The correlationship between ABP and laboratory examinations:There were significant difference between normotensive and hypertensive women in the indexes of liver function,renal function and clotting function.For pregnant women with hypertension,Cr had positive correlation with nDBP,casual SBP and casual DBP(P＜0.05).Bun had positive correlation with casual SBP and casual DBP(P＜0.05).ALT had zero correlation with ABP and CBP.And dSBP,dDBP,nSBP,nDBP had negative correlation with fetal weight(P＜0.05).ConclusionsThe blood pressure of pregnat women with hypertension showed circadian arrhythm,noctual hypertension and elevation of DBP.BP varieties,especially the elevation of DBP,had linear correlation with fetal weight and renal damage.Therefore, the elevation of DBP had more important significance for clinical work.ABPM can overcome the shortcomings of casual blood pressure measurement,and find circadian arrhythm in order to instruct clinical work.