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Trial registered on ANZCTR


Registration number
ACTRN12622000982718
Ethics application status
Approved
Date submitted
7/07/2022
Date registered
13/07/2022
Date last updated
13/07/2022
Date data sharing statement initially provided
13/07/2022
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effects of different types and intensities of exercise on arterial stiffness and blood pressure throughout pregnancy.
Scientific title
The effects of three different training modalities and intensities on arterial stiffness and blood pressure completed weekly throughout pregnancy: A longitudinal randomised cross-over trial
Secondary ID [1] 307505 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
pregnancy 326929 0
Condition category
Condition code
Physical Medicine / Rehabilitation 324116 324116 0 0
Other physical medicine / rehabilitation
Reproductive Health and Childbirth 324132 324132 0 0
Normal pregnancy

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Eligible participants will provide informed consent prior to taking part in the exercise sessions. Women can be recruited from 10 weeks of gestation, with the exercise trials to take place up until 36 weeks of gestation.

The participants will be required to attend three exercise sessions weekly at the exercise clinic for the duration of their pregnancy. They will also be asked to complete a questionnaire prior to the first session to gain characteristics of the included populations so that this data can be used as cofactors in the statistical analysis. Participants will be asked to complete a 24-hour food diary prior to the first session. They will then be asked to avoid high sodium foods in the 24 hours prior to each session. The participants will be provided with a list of high sodium foods to avoid.

The three exercise sessions at will be conducted by Accredited Exercise Physiologists with at least one year experience.

Participants will report to the clinic in a fed state following 48 hours of no strenuous physical activity, having consumed no caffeine on the day of testing. The initial session will involve a submaximal graded exercise test.

The following submaximal treadmill protocol will be adhered to:

Submaximal familiarisation test – Cornell Protocol
- Submaximal test performed on the treadmill.
- Measures will include: Arterial stiffness (AS) (resting), heart rate (HR) (every minute), BP (every stage), MAP (every stage), RPE (Borg 6-20 scale) (every minute), predicted Vo2 max (calculated using HR)
- Subjects will be familiarised with the equipment (treadmill, SphygmoCor, sphygmomanometer, HR monitor, RPE scale)
- Tests will be terminated once subjects reach 85% of age predicted HRmax. American College of Sports Medicine (ACSM) equations will be used to calculate the estimated aerobic capacity (Vo2 = 0.1(speed)+1.8(speed)(fractional grade)+3.5).

Cornell treadmill protocol
Stage - minute - speed km/h - Gradient %
1 - 2 - 2.74 - 0
2 - 4 - 2.74 - 5
3 - 6 - 2.74 - 10
4 - 8 - 3.38 - 11
5 - 10 - 4.02 - 12
6 - 12 - 4.82 - 13
7 - 14 - 5.47 - 14
8 - 16 - 6.11 - 15
9 - 18 - 6.76 - 16
10 - 20 - 7.4 - 17
11 - 22 - 8.05 - 18

The three exercise sessions will be as follows:

Session 1: 30-35 minute light intensity reformer Pilates session (8-10 RPE, 45-60% age predicted heart rate max (PHRmax))
This session will consist of low impact exercises performed on a reformer with a specific focus on core, pelvic floor and the deep hip stabilising muscles. The exercises involved will be modified when necessary to accommodate the physical changes that occur during pregnancy.

Session 2: Moderate intensity resistance training (RPE 11-13, 55-70% PHRmax)
This session will involve low impact resistance training exercise performed with bodyweight, resistance bands, free weights and machine weights. All major muscle groups of the body will be targeted. The exercises involved will be modified when necessary to accommodate the physical changes that occur during pregnancy.

Session 3: Vigorous intensity interval training
VIIT 4x4 protocol
The vigorous intensity interval session will consist of a light 5 min warm up and cool down on a treadmill (9-11 RPE, 45-60% PHRmax). The participants will then perform four, four-minute intervals of vigorous intensity walking (RPE 14-16, 70-85% HRmax) interspersed with four, three-minute intervals of moderate intensity walking (RPE 11-13, ~65% HRmax).
Treadmill walking will be used for this session.

All exercise sessions will be performed individually under constant supervision of the exercise physiologist.
Intervention code [1] 323967 0
Treatment: Other
Comparator / control treatment
Light intensity Reformer Pilates session will be used as the comparator group to compare the three types/intensities of exercise.
Control group
Active

Outcomes
Primary outcome [1] 331924 0
Change in arterial stiffness as measured by pulse wave velocity using a SphygmoCor system
Timepoint [1] 331924 0
Measured at 3 timepoints in each session:
Following 5 minutes of supine rest pre exercise.
Immediately following exercise.
5-10 minutes post exercise.
Primary outcome [2] 331925 0
Change in blood pressure measured with sphygmomanometer & stethoscope (manual reading)
Timepoint [2] 331925 0
Measured at 3 timepoints in each session:
Following 5 minutes of supine rest pre exercise.
Immediately following exercise.
5-10 minutes post exercise.
Primary outcome [3] 331926 0
Mean Arterial Pressure calculated from SBP and DBP (formula > MAP = (SBP + (2DBP))/3)
Timepoint [3] 331926 0
Measured at 3 timepoints in each session:
Following 5 minutes of supine rest pre exercise.
Immediately following exercise.
5-10 minutes post exercise.
Secondary outcome [1] 411600 0
Augmentation index measured as pulse wave analysis using a SphygmoCor system
Timepoint [1] 411600 0
Measured at 3 timepoints in each session:
Following 5 minutes of supine rest pre exercise.
Immediately following exercise.
5-10 minutes post exercise.
Secondary outcome [2] 411601 0
Heart rate measured using HR monitor chest strap
Timepoint [2] 411601 0
Measured constantly throughout each session
Secondary outcome [3] 411602 0
Foetal heart rate measured with Foetal Doppler
Timepoint [3] 411602 0
Measured at 3 timepoints in each session:
Following 5 minutes of supine rest pre exercise.
Immediately following exercise.
5-10 minutes post exercise.
Secondary outcome [4] 411603 0
Rating of perceived exertion (RPE) reported by the participant on the Borg Scale (6-20)
Timepoint [4] 411603 0
Measured during each session.
Session 1 & 2: every 5 minutes of exercise
Session 3: every minute of exercise
Secondary outcome [5] 411684 0
Central blood pressure measured using a SphygmoCor system
Timepoint [5] 411684 0
Measured at 3 timepoints in each session:
Following 5 minutes of supine rest pre exercise.
Immediately following exercise.
5-10 minutes post exercise.

Eligibility
Key inclusion criteria
Pregnant women less than 30 weeks gestation, willing to visit the exercise clinic 3 times per week for exercise sessions.
Minimum age
18 Years
Maximum age
40 Years
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Diagnosed gestational health conditions that are considered absolute contraindications to exercise:
Ruptured membranes, premature labour
Persistent second or third trimester bleeding/placenta previa
Pregnancy-induced hypertension or pre-eclampsia
Incompetent cervix
Evidence of intrauterine growth restriction
High-order pregnancy (e.g., triplets)
Uncontrolled Type I diabetes, hypertension or thyroid disease, other serious cardiovascular, respiratory or systemic disorder

Study design
Purpose of the study
Prevention
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Assuming 80% power, two sided a=0.05, within subject correlation of 0.8 and assuming a small between condition effect size of 0.25 the required sample is 12 participants. To
account for a 20-30% drop out rate 15 participants will be recruited. These numbers are based on a previous study which found a higher pulse wave velocity following 10 minute bouts of moderate intensity walking when compared to 30 minute bouts in middle aged adults (p=0.02).

In order to determine the influence of exercise modality on changes in vascular function, linear mixed models will be used with participant ID included as a random effect within each model and exercise mode as a fixed effect. Separate models will be used for each dependent variable. The significance level will be set a p = 0.05. In order to determine the magnitude of any differences, Cohen’s d effect size (ES) statistic will also be calculated along with 90% confidence limits (CL). These ES will be interpreted as 0-0.20, trivial, 0.20-0.60, small, 0.60-1.20, moderate, and >1.20, large. The effect will be deemed clear if the confidence limits do not span both 0.20 and -0.20 ES. Reliability of outcome measures will be assessed using coefficient of variation.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
15/02/2021
Date of last participant enrolment
Anticipated
30/09/2022
Actual
Date of last data collection
Anticipated
31/01/2023
Actual
Sample size
Target
15
Accrual to date
10
Final
Recruitment in Australia
Recruitment state(s)
QLD

Funding & Sponsors
Funding source category [1] 311785 0
University
Name [1] 311785 0
Australian Catholic University
Country [1] 311785 0
Australia
Primary sponsor type
Individual
Name
Courtney Giles
Address
ACU Banyo Campus:
1100 Nudgee Road, Banyo, Brisbane, 4014, QLD
Country
Australia
Secondary sponsor category [1] 313254 0
None
Name [1] 313254 0
Address [1] 313254 0
Country [1] 313254 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311229 0
ACU's Human Research Ethics Committee
Ethics committee address [1] 311229 0
Level 16, Tenison Woods House, 8-20 Napier Street, North Sydney NSW 2060
Ethics committee country [1] 311229 0
Australia
Date submitted for ethics approval [1] 311229 0
16/04/2020
Approval date [1] 311229 0
31/08/2020
Ethics approval number [1] 311229 0
2020-103H

Summary
Brief summary
In this study we will be looking at the effects of vigorous intensity exercise during each trimester of pregnancy on blood pressure and blood vessels, as well as foetal heart rate. More specifically we want to see if exercising at a higher intensity may be more beneficial to vascular function during pregnancy. During pregnancy adaptations occur to the circulatory system to support the growing foetus. Sometimes these changes can result in negative health outcomes for the mother and the baby, e.g. gestational hypertension and pre-eclampsia. Exercise during pregnancy has been shown to have a range of benefits, including reducing blood pressure and the risk of pre-eclampsia. Higher intensity exercise has been shown to have more benefits on blood pressure in non-pregnant populations, however research on the effects during pregnancy is currently lacking.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 120394 0
Miss Courtney Giles
Address 120394 0
Australian Catholic University, Banyo Campus
1100 Nudgee Road, Banyo, 4014, QLD
Country 120394 0
Australia
Phone 120394 0
+61 439084914
Fax 120394 0
Email 120394 0
courtneygiles@myacu.edu.au
Contact person for public queries
Name 120395 0
Miss Courtney Giles
Address 120395 0
Australian Catholic University, Banyo Campus
1100 Nudgee Road, Banyo, 4014, QLD
Country 120395 0
Australia
Phone 120395 0
+61 439084914
Fax 120395 0
Email 120395 0
courtneygiles@myacu.edu.au
Contact person for scientific queries
Name 120396 0
Miss Courtney Giles
Address 120396 0
Australian Catholic University, Banyo Campus
1100 Nudgee Road, Banyo, 4014, QLD
Country 120396 0
Australia
Phone 120396 0
+61 439084914
Fax 120396 0
Email 120396 0
courtneygiles@myacu.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
This is a small sample size and we don't want the data to be potentially re-identifiable.
The aggregate data may be made available upon request to the Principle Investigator.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.