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Trial registered on ANZCTR


Registration number
ACTRN12623000442606
Ethics application status
Approved
Date submitted
12/04/2023
Date registered
1/05/2023
Date last updated
25/08/2024
Date data sharing statement initially provided
1/05/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Measurement of Sleep Position in Pregnancy
Scientific title
High resolution measurement of sleep position during pregnancy and the impact on infant birthweight.
Secondary ID [1] 309285 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
pregnancy 329447 0
sleep position 329448 0
infant birthweight 329449 0
Condition category
Condition code
Reproductive Health and Childbirth 326385 326385 0 0
Normal pregnancy

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Sleeping position during pregnancy will be objectively measured by the GENEActiv raw data accelerometer overnight for 7 consecutive nights in the participants home, between 32-36 weeks of gestation.
The GENEActiv will be worn around the top of the abdomen attached to a stretchy material belt. It will be worn by the participant from when they first get into bed at night until when they wake and start their day in the morning.
Intervention code [1] 325721 0
Early Detection / Screening
Comparator / control treatment
observational study - no control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 334243 0
percentage of total sleep time in the supine position defined by traditional position sensors (-45 degrees through to 45 degrees) – as measured with the GENEActiv raw data accelerometer.
Timepoint [1] 334243 0
Average of 7 consecutive nights at 32-36 weeks gestation.
Primary outcome [2] 334244 0
percentage of total sleep time in the fully supine position as measured by the GENEActiv raw data accelerator, defined as (-15 to 15 degrees with fully supine defined as 0 degrees).
Timepoint [2] 334244 0
average of 7 consecutive nights at 32-36 weeks of gestation
Secondary outcome [1] 419961 0
infant birthweight z scores corrected for infant sex and gestational age, obtained by review of medical records
Timepoint [1] 419961 0
at birth
Secondary outcome [2] 419962 0
difference in percentage of supine sleep between those who do and do not use pregnancy pillows – pillow use data collected via sleep diary.
Timepoint [2] 419962 0
average of 7 consecutive nights at 32-36 weeks gestation
Secondary outcome [3] 419963 0
Percentage of concordance between comparison of objective versus self-reported sleep onset position – based on the GENEActiv versus the sleep diary.
Timepoint [3] 419963 0
Each of the 7 consecutive nights at 32-36 weeks gestation
Secondary outcome [4] 421261 0
percentage of total sleep time in a "mild lateral tilt" as measured by the GENEActiv raw data accelerator, defined as (-30 to -15 or 15 to 30 degrees with fully supine defined as 0 degrees).
Timepoint [4] 421261 0
average of 7 consecutive nights at 32-36 weeks of gestation
Secondary outcome [5] 421262 0
percentage of total sleep time in a "moderate lateral tilt" as measured by the GENEActiv raw data accelerator, defined as (-45 to -30 or 30 to 45 degrees with fully supine defined as 0 degrees).
Timepoint [5] 421262 0
average of 7 consecutive nights at 32-36 weeks of gestation
Secondary outcome [6] 421263 0
Percentage of concordance between comparison of objective versus self-reported "did you sleep on your back last night" – based on the GENEActiv versus the sleep diary.
Timepoint [6] 421263 0
Each of the 7 consecutive nights at 32-36 weeks gestation

Eligibility
Key inclusion criteria
Persons with a singleton pregnancy in the third trimester (28 weeks of gestation onward), capable of giving informed consent.
Minimum age
18 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
known fetal abnormalities or pregnancy complications including pre-eclampsia, gestational diabetes mellitus, fetal growth restriction, smokers, multiple pregnancy (twins, triplets), under 18 years of age, unable to give informed consent.

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
Statistical Power
As the primary aim of this study is to gather exploratory pilot data to quantify sleeping position more accurately and reliably, a power calculation cannot be performed for this analysis. Due to the paucity of data in this area it is difficult to calculate the required sample size for the second exploratory aim of this study. However, a previous study by the CIA Dr. Wilson (ACTRN12620000371998p) showed that women who spent more than a quarter of the night sleeping supinely had a significantly lower infant birthweight (2770 ± 1000g) than women who spent less than a quarter of the night in supine sleep (3279 ± 837g, p = .0003). Based on this, to identify a reduction in birthweight from 3279g to 2770g between nonsupine vs. supine sleepers would require a sample size of 85 for a power of 80% at an alpha level of 0.05.

Statistical methods
Aim 1 – In order to characterise sleep position during pregnancy, the percentage of time spent in the supine position each night will be calculated by different definitions of supine sleep and compared –
- Traditional position sensor definition of supine sleep; i) 0 (fully supine) to 45 degrees lateral in both directions.
- Degree of “roll” as an interval variable; ii) 0 (fully supine) to 15 degrees, iii) 15 – 30 degrees and iii) 30 - 45 degrees.
- Degree of “roll” as a continuous variable, from which circular histograms and cumulative frequency-based statistics can be produced.
- Data will be analysed to determine the variability in sleep position across the week, as to whether pregnant women can be classified as primarily supine sleepers, primary lateral sleepers, or a mixture of both.

Secondary analysis will be performed to determine –
o whether women using commercially available pregnancy pillows behind the back reduces the amount of supine sleep overnight (supine position data will likely be skewed – Mann-Whitney test).
o the accuracy of self-reported back sleeping compared to position measured with the GENEActiv.
Aim 2 – to determine whether supine sleep during pregnancy is related to infant birthweight, multivariate regression analysis adjusting for BMI and late pregnancy complications will be conducted using generalised linear models to examine if percentage of total sleep time in the supine position is related to infant birthweight. This analysis will also allow determination of whether fully supine sleep (0 – 15 degree tilt) is a stronger predictor of infant birthweight than supine sleep as a categorical variable (0 – 45 degree tilt).

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
15/05/2023
Actual
14/06/2023
Date of last participant enrolment
Anticipated
2/10/2024
Actual
Date of last data collection
Anticipated
30/10/2024
Actual
Sample size
Target
85
Accrual to date
80
Final
Recruitment in Australia
Recruitment state(s)
QLD
Recruitment hospital [1] 24499 0
Redcliffe Hospital - Redcliffe
Recruitment postcode(s) [1] 40088 0
4020 - Redcliffe

Funding & Sponsors
Funding source category [1] 313480 0
Hospital
Name [1] 313480 0
Metro North Collaborative Research Grant
Country [1] 313480 0
Australia
Primary sponsor type
Hospital
Name
Metro North
Address
Metro North Research
Level 7, Block 7, Royal Brisbane and Women's Hospital
Cnr Butterfield St and Bowen Bridge Road
Herston QLD 4029
Country
Australia
Secondary sponsor category [1] 315253 0
None
Name [1] 315253 0
NA
Address [1] 315253 0
NA
Country [1] 315253 0
Other collaborator category [1] 282624 0
University
Name [1] 282624 0
The University of Queensland
Address [1] 282624 0
St Lucia QLD 4067
Country [1] 282624 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 312671 0
Metro North HREC
Ethics committee address [1] 312671 0
Metro North Office of Research
Level 7, Block 7,
Royal Brisbane and Women's Hospital
Cnr Butterfield St and Bowen Bridge Road
Herston QLD 4029
Ethics committee country [1] 312671 0
Australia
Date submitted for ethics approval [1] 312671 0
15/09/2022
Approval date [1] 312671 0
30/11/2022
Ethics approval number [1] 312671 0
HREC/2022/MNHA/88879

Summary
Brief summary
Following on from the meta-analysis findings that pregnant women who subjectively report going to sleep on their back are at higher risk of stillbirth, the purpose of this project is to objectively characterise overnight sleep position during pregnancy by using more precise measurement techniques over a longer period of time. This assessment of supine sleep during pregnancy will also help to collect data on the relationship between sleeping on the back during pregnancy and lower fetal birthweight as a risk factor for stillbirth, to inform future study designs and power calculations.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 125506 0
Dr Danielle Wilson
Address 125506 0
Sleep Disorders Centre
Level 1 Main Building
The Prince Charles Hospital
Rode Rd Chermside QLD 4032
Country 125506 0
Australia
Phone 125506 0
+61402075862
Fax 125506 0
Email 125506 0
[email protected]
Contact person for public queries
Name 125507 0
Danielle Wilson
Address 125507 0
Sleep Disorders Centre
Level 1 Main Building
The Prince Charles Hospital
Rode Rd Chermside QLD 4032
Country 125507 0
Australia
Phone 125507 0
+61402075862
Fax 125507 0
Email 125507 0
[email protected]
Contact person for scientific queries
Name 125508 0
Danielle Wilson
Address 125508 0
Sleep Disorders Centre
Level 1 Main Building
The Prince Charles Hospital
Rode Rd Chermside QLD 4032
Country 125508 0
Australia
Phone 125508 0
+61402075862
Fax 125508 0
Email 125508 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
individual de-identified participant data underlying published results only
When will data be available (start and end dates)?
After publication - anticipated in early 2025 no end date
Available to whom?
anyone who wishes to access it
Available for what types of analyses?
any purpose
How or where can data be obtained?
via data sharing online repository such as Figshare.


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.