Conical Forearm and Cylindrical Upper Arm Non-Invasive Blood Pressure (NIBP) Measurements in Pregnant Patients

The diagnosis of hypertensive disease during pregnancy is predicated on strict blood pressure thresholds: 140/90 on at least two occasions measured four hours apart for both gestational hypertension and preeclampsia. An improvement in diagnostic accuracy of even 5mm Hg would be significant, as reflected by the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension (ESH) Working Group on Blood Pressure (BP) Monitoring, and the International Organization for Standardization (ISO)consensus for validation of non-invasive blood pressure (NIBP) devices during pregnancy. Given the known inaccuracies of upper arm cylindrical cuff measurements in morbidly obese patients, a conical cuff which provides more accurate measurements will translate into direct patient benefit via more informed diagnosis and management. Fewer women may be exposed to unnecessary treatment, preterm delivery, and/or cesarean section. Recognizing the increasing prevalence of morbid obesity and hypertensive disease amongst pregnant women in the United States, the identification of a more accurate non-invasive cuff is desperately needed. Increasing the accuracy of NIBP measurements on Labor and Delivery has the potential to directly impact the management of tens of thousands of morbidly obese pregnant women diagnosed with hypertensive disease in the United States every year. Establishing the level of agreement between conical forearm and cylindrical upper arm cuffs will shed light on the presence and magnitude of any disparity between measurement methods. STUDY ENDPOINTS: Primary Outcome Measures: * Agreement between conical and cylindrical cuff systolic blood pressure across groups * Agreement between conical and cylindrical cuff diastolic blood pressure across groups Secondary Outcome Measures: • Agreement between conical and cylindrical cuff mean arterial pressure