Clinical trial NCT04059822: Slow and Deep Breathing to Lower Blood Pressure in Women With Pregnancy-induced Hypertension
Official title: Effects of Slow and Deep Breathing on Reducing Obstetric Intervention in Women With Pregnancy-induced Hypertension:A Feasibility Study
Study type: INTERVENTIONAL
Overall status: SUSPENDED
Phase: NA
Conditions: Pregnancy-Induced Hypertension
Keywords: Slow and deep breathing
Feasibility study
Lead sponsor: Bournemouth University
Sponsor class: OTHER
First posted: 2019-08-16
Enrollment: 67
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: All participants will take part in the slow and deep breathing daily exercises.
Primary purpose: TREATMENT

Brief summary: 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.

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Adherence to the breathing exercise intervention
timeFrame: Up to 22 weeks (From enrolment to giving birth)
Secondary outcomes:
measure: Proportion of women referred to obstetric-led care
timeFrame: Up to 22 weeks (From enrolment to giving birth)
Other outcomes:
measure: Proportion of women eligible to participate in study
timeFrame: 5 months (From start to end of recruitment period)
measure: Recruitment rates of participation using a hospital antenatal unit
timeFrame: 5 months (From start to end of recruitment period)
measure: Proportion of women who would be willing to be randomised in future trials
timeFrame: 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
measure: Adherence to self-monitoring of daily blood pressure
timeFrame: Up to 22 weeks (From enrolment to giving birth)
measure: Proportion of women withdrawing
timeFrame: Up to 22 weeks (From enrolment to giving birth)
measure: Difference in blood pressure
timeFrame: Up to 22 weeks (From enrolment to giving birth)
measure: Practicality of protocol in delivering slow and deep breathing as an intervention to treat high blood pressure during pregnancy.
timeFrame: 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
measure: Heart rate responses to slow and deep breathing
timeFrame: Day 1
measure: Blood pressure responses to slow and deep breathing
timeFrame: Day 1
measure: Stroke volume responses to slow and deep breathing
timeFrame: Day 1
measure: Cardiac output responses to slow and deep breathing
timeFrame: Day 1
Locations:
city: Bournemouth
country: United Kingdom
facility: Bournemouth University
city: Poole
country: United Kingdom
facility: University Hospitals Dorset NHS Foundation Trust
Study officials:
affiliation: Postgraduate Researcher
name: Malika Felton
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.