Non-invasive Versus Invasive Blood Pressure Measurement in the Morbidly Obese Parturient (BMI >= 40 kg/m2) With Severe Preeclampsia: A Comparison of Direct Arterial Blood Pressure Measurements With Readings Obtained Using Either Large Cylindrical or Novel Conical Bariatric Upper Arm Blood Pressure Cuffs

A morbidly obese [Body Mass Index (BMI) ≥ 40 kg/m2] pregnant woman is at singular risk for all the complications of pregnancy, most notably preeclampsia (PE). Furthermore a woman who is already chronically hypertensive is likely to develop superimposed PE . Uncontrolled systolic hypertension in pregnancy prompts placental abruption, hemorrhagic stroke, and systolic or diastolic heart failure. Accurate blood pressure measurement is therefore a prerequisite to controlling dangerously high systolic blood pressure (SBP) to enable labor and delivery to be conducted safely in association with PE. Precise SBP measurement is also a precondition for clinically testing hypotheses concerning the existence of druggable targets that will allow prolongation of pregnancy in the face of severe PE and /or intra-uterine growth restriction (IUGR) remote from term.

Oscillometric noninvasive blood pressure (NIBP) measurement is the customary standard blood pressure monitoring method most often used in the labor suite and obstetric operating room today. For this purpose a rectangular, cylindrical blood pressure (BP) cuff placed on the upper arm is connected to an oscillometric blood pressure device. Yet inaccuracies related to the fact that oscillometric NIBP devices under-read high SBP relative to IBP measurements have been recognized as a potential source of maternal morbidity for years.

The study will compare IBP readings obtained from morbidly obese, severely hypertensive (SBP > 160 mm Hg) parturients with NIBP consecutively measured with new innovative conical Ultracheck Curve BP cuffs and large standard upper arm rectangular cylindrical BP cuffs.