An accurate automated blood pressure device for use in pregnancy and pre-eclampsia: the Microlife 3BTO-A

Objective To assess the accuracy of an automated blood pressure device (Microlife 3BTO-A) in pregnancy and pre-eclampsia according to the British Hypertension Society (BHS) protocol. Design Prospective observational study. Setting Antenatal ward and clinics at Guy's and St Thomas' Hospital, London, UK. Population One hundred and five pregnant women including 35 women with non-proteinuric hypertension and 35 with pre-eclampsia. Methods Two trained observers took nine sequential same-arm measurements from each woman. Measurements alternated between a mercury sphygmomanometer and the device. Main outcome measures Grading criteria of the BHS protocol (A/B grade = pass; C/D grade = fail). Results The device passed the BHS protocol by achieving an A/B grade. It also achieved criteria of the Association for the Advancement of Medical Instrumentation for systolic and diastolic pressures respectively, in normotensive [-0.5 (5.7) mmHg; -0.07 (7.7) mmHg], non-proteinuric hypertensive [-3.3 (6.9) mmHg; -2.4 (6.6) mmHg] and pre-eclamptic pregnancy [-4.1 (6.4) mmHg; -1.3 (7.9) mmHg]. Conclusion The Microlife 3BTO-A can be recommended for use in a pregnant population, including pre-eclampsia, according to the BHS protocol.