NCT07405723

Arm Position and Blood Pressure Measurement Accuracy During Pregnancy

Arm Position and Blood Pressure Measurement Accuracy in Pregnancy: A Randomized Controlled Trial

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 300 (estimated)
• Sponsor: Sheba Medical Center · Other Government
• Sex: Female
• Age: 18 Years – 55 Years
• Healthy volunteers: Accepted

Summary

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.

Detailed description

Blood pressure measurement is a routine and essential component of prenatal care and plays a central role in the diagnosis and management of hypertensive disorders of pregnancy. International and national guidelines recommend measuring blood pressure with the patient seated, after a period of rest, and with the arm supported at heart level. Despite these recommendations, blood pressure in clinical practice is frequently measured with the arm placed in non-standard positions, which may lead to inaccurate readings and potential misclassification of blood pressure status. This study is designed to assess the effect of arm position on blood pressure measurements in pregnant women. This is a single prospective randomized crossover trial conducted across all three trimesters of pregnancy. Randomization of arm position order is performed using a computerized block randomization system with stratification by trimester (first, second, third) and chronic hypertension status. Participants are enrolled during routine visits to a high-risk pregnancy clinic and are assigned to a trimester-specific cohort based on gestational age at the time of enrollment. During a single clinic visit, each participant undergoes multiple blood pressure measurements with the arm positioned in several commonly used positions: supported on a desk at heart level, supported on the lap, and unsupported at the side. To account for natural variability in blood pressure measurements, an additional set of measurements with the arm supported at heart level is obtained. Each participant serves as her own control within the randomized crossover design. Blood pressure measurements are performed by trained nursing staff using a clinically approved automated blood pressure device, following a standardized measurement protocol. All measurements are obtained after a resting period and while the participant is seated comfortably. Participants are recruited across all three trimesters, and analyses are conducted separately by trimester. The primary outcome is the difference in systolic and diastolic blood pressure measurements between arm positions. Secondary analyses evaluate the magnitude and pattern of blood pressure differences across gestational ages and relevant clinical subgroups. This study involves minimal risk and does not alter standard clinical care. The results are intended to improve understanding of how arm positioning influences blood pressure measurements during pregnancy and to inform best practices for accurate blood pressure assessment in prenatal care.

Conditions

• Pregnancy
• Blood Pressure Measurement in Pregnancy
• Hypertensive Disorder of Pregnancy

Interventions

Type	Name	Description
OTHER	Arm Supported at Heart Level	Blood pressure measurements are obtained with the arm supported at heart level while the participant is seated.
OTHER	Arm Supported on Lap	Blood pressure measurements are obtained with the arm supported on the participant's lap while seated.
OTHER	Arm Unsupported at Side	Blood pressure measurements are obtained with the arm unsupported at the participant's side while seated.

Timeline

• Start date: 2026-04-12
• Primary completion: 2026-09-01
• Completion: 2026-12-31
• First posted: 2026-02-12
• Last updated: 2026-04-16

Locations

1 site across 1 country: Israel