Can We Use the Omron T9P Automated Blood Pressure Monitor in Pregnancy?

Background. Recent events in our hospital, combined with international recommendations, catalyzed the need to move from mercury sphygmomanometry to automated blood pressure (BP) recording in pregnancy. Aim. To test the accuracy of the Omron T9P automated BP recorder in pregnant women, using mercury sphygmomanometry as the gold standard. Setting. Antenatal clinics and obstetric day assessment unit, St George Hospital, Sydney. Participants. Eighty-five pregnant women, 11% of whom were receiving antihypertensives. Methods. Differences in both systolic and diastolic BP between the T9P Omron device and mercury sphygmomanometer were obtained for each woman, using sequential automated and mercury BP recordings, as required by a modified British Hypertension Society (BHS) protocol. The accuracy of the device was graded according to the BHS and the Association for the Advancement of Medical Instrumentation (AAMI) standards. Results. The Omron T9P device received an A/A grade according to this modified BHS and AAMI testing process, though the range of the 255 differences was 1-13 for systolic BP and 1-10 for diastolic BP. Conclusions. The Omron T9P device is an accurate device for use predominantly in an outpatient antenatal clinical setting. Further studies are required solely within hypertensive pregnant women before its use can be recommended with certainty in this group.