Is there a role for ambulatory blood pressure monitoring in pregnancy?

Ambulatory blood pressure monitoring (ABPM) has been used in pregnancy for just over 20 years now and is generally well tolerated. Normal values have been established for different gestations; these are slightly higher than conventional blood pressure (BP) in normal pregnancy, presumably reflecting greater activity during the 24h of ABPM recordings. Ambulatory blood pressure monitoring is a better predictor than conventional BP for the development of pre-eclampsia and fetal growth restriction, but it is not sensitive or specific enough to be recommended for these purposes in routine practice. Studies of ABPM have shown that sleep hypertension is common in women with gestational hypertension or pre-eclampsia, but detecting this in routine clinical practice does not aid usual decision making in the pregnancy, including timing of delivery. Studies using ABPM have found that pregnant women who are working outside the home have higher BP than non-working women, but these data should not be interpreted to mean that not working during pregnancy will prevent gestational hypertension or pre-eclampsia. The best role for ABPM is to determine whether women with office hypertension in early pregnancy have true (usually essential) hypertension or white-coat hypertension. The latter can be managed without antihypertensives and pregnancy outcomes appear good, although possibly with a slightly increased incidence of pre-eclampsia. Women who have had pre-eclampsia are at greater life-time risk for cardiovascular diseases; several years postpartum these women have slightly higher ABPM-measured BP than women who had normal pregnancies and a greater propensity to metabolic syndrome.