Arm Position and Blood Pressure Measurement Accuracy During Pregnancy

NCT07405723 | Recruiting

• 1 other identifier: 2177-25-SMC
• Study Type: interventional
• Target: 300
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

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

Keywords

Blood Pressure Measurement; Pregnancy; Arm Position; Hypertensive Disorders of Pregnancy; Prenatal Care; Blood Pressure Accuracy; Randomized Crossover Trial

Outcome Measures

Primary Outcomes (1)

• Difference in Systolic and Diastolic Blood Pressure Between Arm Positions

  The within-participant difference in mean systolic and diastolic blood pressure measurements obtained with the arm supported at heart level, supported on the lap, and unsupported at the side. Blood pressure values are calculated as the mean of triplicate measurements for each arm position.

  At the study visit (single study visit on the day 1 of enrollment)

Secondary Outcomes (5)

• Magnitude of Blood Pressure Differences Between Arm Positions

  At the study visit (single study visit on the day 1 of enrollment)

• Variation in Blood Pressure Differences Across Gestational Age

  At the study visit (single study visit on the day 1 of enrollment)

• Effect of Arm Position on Blood Pressure by Chronic Hypertension Status

  At the study visit (single study visit on the day 1 of enrollment)

• Comparison of Systolic Versus Diastolic Blood Pressure Sensitivity to Arm Position

  At the study visit (single study visit on the day 1 of enrollment)

• Blood Pressure Differences by Singleton Versus Multiple Pregnancy

  At the study visit (single study visit on the day 1 of enrollment)

Study Arms (3)

Arm Supported at Heart Level

EXPERIMENTAL

Blood pressure measurements are obtained with the arm supported at heart level while the participant is seated.

Other: Arm Supported at Heart Level

Arm Supported on Lap

EXPERIMENTAL

Blood pressure measurements are obtained with the arm supported on the participant's lap while seated.

Other: Arm Supported on Lap

Arm Unsupported at Side

EXPERIMENTAL

Blood pressure measurements are obtained with the arm unsupported at the participant's side while seated.

Other: Arm Unsupported at Side

Interventions

Arm Supported at Heart Level OTHER

Blood pressure measurements are obtained with the arm supported at heart level while the participant is seated.

Arm Supported at Heart Level

Arm Supported on Lap OTHER

Blood pressure measurements are obtained with the arm supported on the participant's lap while seated.

Arm Supported on Lap

Arm Unsupported at Side OTHER

Blood pressure measurements are obtained with the arm unsupported at the participant's side while seated.

Arm Unsupported at Side

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Pregnant women aged 18 to 55 years
• Singleton or multiple viable intrauterine pregnancy
• Gestational age corresponding to first, second, or third trimester at the time of enrollment
• Ability to sit upright comfortably for the duration of blood pressure measurements
• Ability to understand the study procedures and provide written informed consent

You may not qualify if:

• Preexisting significant cardiac disease (e.g., arrhythmias, congenital heart disease, severe valvular disease)
• Chronic kidney disease defined as serum creatinine ≥1.5 mg/dL at enrollment
• Significant upper limb or shoulder conditions that may affect arm positioning or blood pressure measurement (e.g., lymphedema, fractures, prior surgery, arteriovenous fistula)
• Neurological or musculoskeletal conditions preventing proper positioning
• Severe preeclampsia, eclampsia, or other acute medical conditions requiring immediate intervention
• Major fetal anomaly
• Intrauterine fetal demise

Sponsors & Collaborators

• Sheba Medical Center: lead

Study Sites (1)

Sheba Medical Center

Ramat Gan, 5265217, Israel

RECRUITING

Related Publications (1)

• Liu H, Zhao D, Sabit A, Pathiravasan CH, Ishigami J, Charleston J, Miller ER 3rd, Matsushita K, Appel LJ, Brady TM. Arm Position and Blood Pressure Readings: The ARMS Crossover Randomized Clinical Trial. JAMA Intern Med. 2024 Dec 1;184(12):1436-1442. doi: 10.1001/jamainternmed.2024.5213.

  PMID: 39373998 BACKGROUND

MeSH Terms

Conditions

Toxemia

Condition Hierarchy (Ancestors)

Infections

Central Study Contacts

Michal Axelrod, MD MPH

CONTACT

+97235302697; michalaxelrod2805@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Obstetrician-Gynecologist

Model Details: Participants undergo blood pressure measurements with the arm placed in multiple positions in a randomized order during a single clinic visit, allowing each participant to serve as her own control.

Study Record Dates

• First Submitted: February 3, 2026
• First Posted: February 12, 2026
• Study Start: April 12, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: April 16, 2026

Record last verified: 2026-04

Locations

IL (1)