AMBULATORY BLOOD-PRESSURE MONITORING DURING PREGNANCY - COMPARISON WITH MERCURY SPHYGMOMANOMETRY

There is little information concerning the relationship between blood pressures obtained by standard mercury sphygmomanometry and ambulatory blood pressure monitoring (ABPM) in pregnancy. We compared readings o btained with these two methods using an Hawksley random zero mercury s phygmomanometer and an Accutracker II ABPM device. Blood pressures wer e compared over 90 min with the pregnant woman seated and, in a separa te study, over 30 min during standing and ambulation. When pregnant wo men were seated, the ABPM overestimated the systolic blood pressure (B P) by 5 (3,6) mm Hg (mean, 95% confidence limits) (P < .001) and under estimated diastolic phase IV readings by 7 (- 9, - 6) mm Hg W < .001) and phase V readings by 3 (- 5, - 1) mm Hg (P < .01). Eighty-three per cent of systolic readings agreed within 10 mm Hg. Seventy-six percent of diastolic phase V (but only 45% of phase IV) readings agreed within 6 mm Hg. When pregnant women were ambulatory, the ABPM overestimated systolic BP by 7 (4,10) mm Hg (P < .001) and underestimated diastolic phase IV readings by 6 (- 8, - 4) mm Hg W < .001) and phase V readings by 4 (- 6, - 2) mm Hg (P < .01). Eighty percent of systolic readings agreed within 10 mm Hg. Fifty-five percent of diastolic phase V and 50 % of diastolic phase IV readings agreed within 6 mm Hg. The Accutracke r II blood pressure readings are reasonably comparable to those of mer cury sphygmomanometry in pregnant women, particularly when assessing g roup data. Such devices must be compared with mercury recordings in in dividual pregnant women before they are applied to clinical practice.