Slow and Deep Breathing to Lower Blood Pressure in Women With Pregnancy-induced Hypertension

Effects of Slow and Deep Breathing on Reducing Obstetric Intervention in Women With Pregnancy-induced Hypertension:A Feasibility Study

This study evaluates the effect of slow and deep breathing on lowering blood pressure in women with pregnancy-induced hypertension. Slow and deep breathing will be practised daily for 10 minutes from enrolment until the woman gives birth. This feasibility study aims to investigate the practicality of conducting a proposed future randomised controlled trial.

Study Overview

• Status: Suspended
• Conditions: Pregnancy-Induced Hypertension
• Intervention / Treatment: Other: Slow and deep breathing

Detailed Description

In addition to the slow and deep breathing intervention the women will undertake a short protocol investigating the physiological responses to slow and deep breathing during their initial meeting. The women will undertake 4 separate 5-min breathing exercises with a 5 minute rest period between each exercise. The breathing exercises are normal breathing, and fixed breathing frequencies of 4, 6 and 8 breaths per minute. Blood pressure, heart rate and breathing rate will be monitored continuously, and non-invasively, throughout each breathing protocol.

The women will also have the opportunity to provide feedback on the intervention and their experiences in an online survey at 36 weeks gestation.

• Study Type: Interventional
• Enrollment (Estimated): 67
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Malika Felton; Phone Number: +441202 961845; Email: mfelton@bournemouth.ac.uk
• Study Contact Backup: Name: Suzy Wignall; Phone Number: +441202 961073; Email: swignall@bournemouth.ac.uk

Study Locations

• United Kingdom
  • Bournemouth, United Kingdom, BH8 8GP
    • Bournemouth University
  • Poole, United Kingdom
    • University Hospitals Dorset NHS Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosed with pregnancy-induced hypertension (PIH). Defined as "new hypertension presenting after 20 weeks of pregnancy without significant proteinuria (urinary protein:creatinine ratio greater than 30mg/mmol" by NICE guidelines (2010) OR diagnosed as having one-off high blood pressure but at risk of developing PIH;
• Single pregnancy;
• Capable of giving informed consent;
• Age over 18.

Exclusion Criteria:

• Under 18 years old;
• Referred immediately to obstetric-care after PIH diagnosis for an immediate intervention, with systolic blood pressure over 160 mmHg or diastolic blood pressure over 100 mmHg;
• Multiple pregnancy (twins, triplets, etc.);
• Current smoker;
• Current diagnosis of respiratory diseases; asthma, COPD (Chronic Obstructive Pulmonary disease), bronchitis. (A previous occurrence or diagnosis that has not been present for longer than 1 year ago does not exclude participants, i.e. childhood asthma);
• Allergy/reaction to gel used on ECG tabs;
• Vulnerable participants who are unable to give informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Slow and deep breathing; Daily practice of slow and deep breathing for 10 minutes per day. Breathing frequency will be 6 breaths per minute, with participants accessing a video aid to help guide their breathing. Breathing exercises will be conducted from enrolment until birth (maximum ~20 weeks if enrolment at 20 weeks gestation until ~40 weeks gestation birth)	Other: Slow and deep breathing; Please see arm description

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adherence to the breathing exercise intervention	Proportion of days breathing exercise completed per participant and average proportion of days breathing exercise completed	Up to 22 weeks (From enrolment to giving birth)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of women referred to obstetric-led care	Referral to obstetric-led care will be on the grounds of a test result of 30 mg/mmol^1 in a spot urinary protein, symptom exacerbation and/or increase in systolic and/or diastolic blood pressure	Up to 22 weeks (From enrolment to giving birth)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of women eligible to participate in study	Proportion of women eligible to participate in the study (using inclusion and exclusion criteria) against number of women who attend the antenatal unit for high blood pressure	5 months (From start to end of recruitment period)
Recruitment rates of participation using a hospital antenatal unit	Proportion of women participating in the study against number of eligible women who attend the antenatal unit	5 months (From start to end of recruitment period)
Proportion of women who would be willing to be randomised in future trials	Proportion of women who would be willing to be randomised in a future trial (asked in post-questionnaire) against those who would not be willing to be randomised	Between gestational age 36 weeks and birth. If participant gives birth prior to 36 weeks they will be invited to participate in the questionnaire when appropriate, but before 36 weeks
Adherence to self-monitoring of daily blood pressure	Proportion of days blood pressure recorded per participant and average proportion of days blood pressure recorded	Up to 22 weeks (From enrolment to giving birth)
Proportion of women withdrawing	Proportion of women who do not contribute data due to premature delivery, drop-out or worsening high blood pressure	Up to 22 weeks (From enrolment to giving birth)
Difference in blood pressure	Average week 1 blood pressure compared with average last week blood pressure (last week prior to giving birth)	Up to 22 weeks (From enrolment to giving birth)
Practicality of protocol in delivering slow and deep breathing as an intervention to treat high blood pressure during pregnancy.	Women's perceptions of the intervention, as assessed using the post-questionnaire. The questionnaire includes open ended questions on experiences and barriers to completing the intervention. Likert scale (strongly agree, agree, uncertain, disagree, strongly disagree) questions are also included.	Between gestational age 36 weeks and birth. If participant gives birth prior to 36 weeks they will be invited to participate in the questionnaire when appropriate, but before 36 weeks
Heart rate responses to slow and deep breathing	Differences in heart rate between breathing protocols (5 minutes of breathing at 4, 6, and 8 breaths per minute and normal breathing)	Day 1
Blood pressure responses to slow and deep breathing	Differences in blood pressure between breathing protocols (5 minutes of breathing at 4, 6, and 8 breaths per minute and normal breathing)	Day 1
Stroke volume responses to slow and deep breathing	Differences in stroke volume between breathing protocols (5 minutes of breathing at 4, 6, and 8 breaths per minute and normal breathing)	Day 1
Cardiac output responses to slow and deep breathing	Differences in cardiac output between breathing protocols (5 minutes of breathing at 4, 6, and 8 breaths per minute and normal breathing)	Day 1

Collaborators and Investigators

• Sponsor: Bournemouth University
• Investigators: Principal Investigator: Malika Felton, Postgraduate Researcher

Publications and helpful links

General Publications

• Felton M, Hundley VA, Grigsby S, McConnell AK. Effects of slow and deep breathing on reducing obstetric intervention in women with pregnancy-induced hypertension: a feasibility study protocol. Hypertens Pregnancy. 2021 Feb;40(1):81-87. doi: 10.1080/10641955.2020.1869250. Epub 2021 Jan 19.

Study record dates

Study Major Dates

• Study Start (Actual): January 14, 2020
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: August 13, 2019
• First Submitted That Met QC Criteria: August 15, 2019
• First Posted (Actual): August 16, 2019

Study Record Updates

• Last Update Posted (Estimated): February 7, 2024
• Last Update Submitted That Met QC Criteria: February 6, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Keywords: Feasibility study; Slow and deep breathing
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Hypertension; Hypertension, Pregnancy-Induced
• Other Study ID Numbers: 251062

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No