Accuracy of inflationary versus deflationary oscillometry in pregnancy and preeclampsia: OMRON-MIT versus OMRON-M7.

Objective: To assess the accuracy of the OMRON-MIT (inflationary) and OMRON-M7 (deflationary) devices for measuring blood pressure in a pregnant population, including women with preeclampsia, according to the British Hypertension Society protocol.

Methods: Forty-five pregnant women, including 15 with preeclampsia, were recruited at a large teaching hospital. Nine sequential same arm measurements were taken from each patient alternating between the test device and mercury sphygmomanometry. Both devices were assessed in the same women. Data were analysed according to the British Hypertension Society protocol.

Results: The OMRON-MIT achieved an A/A grade in both pregnancy and preeclampsia with an overall mean difference (SD) of -1.3 (5.6) mmHg and 0.4 (5.6) mmHg for systolic and diastolic pressures, respectively. The OMRON-M7 achieved an A/A grade in pregnancy and a B/B grade in preeclampsia with an overall mean difference (SD) of -5.3 (6.6) mmHg and -3.5 (6.9) mmHg.

Conclusion: Both the OMRON-MIT and the OMRON-M7 can be recommended for use in pregnancy and preeclampsia. Inflationary oscillometry (OMRON-MIT) was more accurate in preeclampsia.