Objectives To assess the Microlife 3AS1–2, a semi-automated oscillometric BP device, compared to mercury sphygmomanometry for use in pregnancy and pre-eclampsia in a low resource setting, according to the requirements of the British Hypertension Society (BHS) Protocol¹ and the International Organisation of Standardisation (ISO).²

Methods Prospective observational study, using validation methods recommended by the BHS. 45 pregnant subjects were recruited, including 15 with pre-eclampsia, 10 in their second trimester, 10 from their third trimester and 10 with an arm circumference >35 cm, from Kimberley Hospital, South Africa. All participants were provided with written consent. any subject with cardiac arrhythmia or unclear Korotkoff sounds was excluded.

Results The Microlife 3AS1–2 device achieved an overall B/A grade, with an A/A grade in pregnancy excluding pre-eclampsia (n = 30) and passed all the BHS protocol requirements. The device achieved the ISO standard for mean difference and standard deviation (≤ 5 ± 8 mmHg) in pregnancy (including pre-eclampsia).

Conclusion The Microlife 3AS1–2 device can be recommended for use in pregnancy, including pre-eclampsia, according to BHS and ISO protocols. As well as demonstrating accuracy in a low-resource pregnant population, it also fulfils all of the requirements stipulated by the World Health Organisation for an automated device suitable for use in a low-resource setting. This makes it the ideal device for use in antenatal clinics and primary health-care facilities in low- and middle-income countries.

References

1. International Standard (ISO). Non-invasive sphygmomanometers. Part 2: Clinical investigation of automated measurement type. 2013

2. O’Brien E, et al. The British Hypertension Society protocol for the evaluation of blood pressure measuring devices. J Hypertens. 1993;11(Suppl 2):S43–S62