Title: CLINICAL ABSTRACTS: WOMEN'S HEALTH , Modern Medicine, 00268070, Jan2000, Vol. 68, Issue 1
Database: Health Source - Consumer Edition
24-Hour blood pressure better at predicting pregnancy outcomes
New data point to the superiority of 24-hour blood pressure (BP) monitoring over office BP for predicting pregnancy outcomes.
STUDY DESIGN. The investigators used 24-hour BP monitoring to assess a group of pregnant women with a high office BP (n=148) or a normal office BP (n=106) during their third trimester of pregnancy. All participants were followed to the completion of their pregnancy in order to permit the researchers to establish the prevalence and prognostic value of white coat hypertension in the third trimester. The primary outcome measures were duration of pregnancy, incidence of transient gestational hypertension, preeclampsia and edampsia, incidence of cesarean delivery, placental and neonatal weight, Apgar score, and duration of hospital stay of the mother and her newborn.
In the study, white coat hypertension was defined as the presence of an elevated office BP (>/= 140 mm Hg systolic and/or 90 mm Hg diastolic BP) but a normal mean 24-hour, daytime, and nighttime systolic and diastolic BP. Women with higher 24-hour BP were considered to have true hypertension.
RESULTS. Data on 7 of the participants were not included in the final analysis because their 24-hour BP monitoring values did not pass the inclusion criteria. Of the 144 remaining women with a high office BP, 42 (29%) were classified as having white coat hypertension. The mean duration of pregnancy was similar among the group with white coat hypertension and the normotensive group (40 weeks) but was shorter in the group with true hypertension (38 weeks).
The incidence of preeclampsia was not significantly different between the group with white coat hypertension and normotensive group (7% vs 6%, respectively) but was markedly higher in the true hypertension group (62%). Overall, 12% of normotensive patients had a cesarean delivery, compared with 45% of the group with white coat hypertension and 41% of the true hypertension group. Mean neonatal weight was lower in the true hypertension group than in the normotensive and white coat hypertension groups, which did not differ. The mean duration of hospital stay for newborns was similar among the normotensive and the white coat hypertension groups but was longer in the true hypertension group.
The authors conclude that nearly one third of women with high office BP in the third trimester really have white coat hypertension and that "this condition carries a prognostic impact that, as far as the outcome of pregnancy is concerned, differs from the normotensive women only for a greater probability of undergoing cesarean delivery, a slightly lower Apgar score at 1 minute, and a higher incidence of transient late gestational hypertension."
Furthermore, they note that the higher frequency of cesarean delivery in the group with white coat hypertension most likely is due to decision-making based on office BP. Accordingly, they recommend that a randomized trial be conducted to examine the effects of therapeutic decisions based on office BP compared with 24-hour BP in women with uncomplicated hypertension during their third trimester.