White coat hypertension and pregnancy outcome

The presence and outcome effect of white coat hypertension in pregnancy was determined with 24-h ambulatory blood pressure (BP) monitoring. Sixty wome n presenting with high clinic BP (greater than or equal to 140/90 mm Hg) in the second trimester were included. Patients were divided into two groups based on daytime ambulatory BP findings: <135/85 mm Hg, white coat hyperten sion (n = 37); greater than or equal to 135/85 mm Hg, 'true' hypertension ( n = 23). Complicated pregnancy outcome was defined as the presence of pre-e clampsia and/or intrauterine growth restriction. Groups were compared for p regnancy outcome and for background and delivery factors. The predictive va lue of ambulatory BP measurements for pregnancy outcome was determined. Pregnancy outcome was better in the white coat hypertension group than in t he true hypertension group: pre-eclampsia-3 (8.1%) vs 13 (56.5%) (P = 0.004 6); intrauterine growth restriction-5 (13.5%) vs 10 (43.4%) (P = 0.0139); a nd preterm delivery-11 (29.7%) vs 15 (65.2%) (P = 0.015). Night-time ambula tory BP measurements were the best predictor of complicated pregnancy, foll owed by daytime and 24-h measurements. We conclude that second trimester ambulatory BP monitoring can be used to d ifferentiate patients who have white coat hypertension, which is associated with a better pregnancy outcome than true hypertension.