Validation of the Microlife WatchBP Home blood pressure device in pregnancy for medium and large arm circumferences

The Microlife WatchBP Home automated blood pressure device was assessed for accuracy in pregnant women of medium (<32 cm) and large (≥32 cm) arm circumference.

The British Hypertension Society validation protocol was modified for the purpose of this study to include women with arm circumference of less than 32 cm (N=51) and greater than or equal to 32 cm (N=46) as two separate arms.

The device achieved an overall A/A grade for medium arm circumference and B/A grade for large arm circumference. The mean±SD device-observer difference was 1.7±6.2 and -0.4±4.4 for systolic and diastolic blood pressure, respectively, for medium arm circumference and 3.0±8.5 and 1.5±5.1, respectively, for large arm circumference. When all women with pre-eclampsia from both groups were pooled (N=23), the device achieved an overall grade of A/A with mean differences of 2.1±7.2 for systolic blood pressure and 1.0±5.6 for diastolic blood pressure.

The Microlife WatchBP Home automated blood pressure device can be recommended for use in pregnant women of all gestations, including those with pre-eclampsia. However, caution is needed for women with large arm circumferences.