Arm Position and Blood Pressure Measurement Accuracy During Pregnancy

Accurate blood pressure measurement is essential during pregnancy, as blood pressure readings guide clinical decisions related to the diagnosis and management of hypertensive disorders of pregnancy. Clinical guidelines recommend measuring blood pressure with the arm supported at heart level; however, in routine practice, blood pressure is often measured with the arm in non-standard positions. This study aims to evaluate how different arm positions affect blood pressure measurements in pregnant women. Pregnant women attending a high-risk pregnancy clinic will undergo blood pressure measurements with the arm placed in several commonly used positions, including supported at heart level, supported on the lap, and unsupported at the side. Each participant will have multiple measurements taken during a single clinic visit. The study is designed as a randomized crossover trial with stratification by trimester and chronic hypertension status, allowing each participant to serve as her own control. Participants will be enrolled across all three trimesters of pregnancy, and results will be analyzed separately for each trimester. The primary outcome is the difference in systolic and diastolic blood pressure measurements between arm positions. The findings of this study may help improve the accuracy of blood pressure measurement during pregnancy and inform clinical practice regarding optimal measurement techniques.