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Trial registered on ANZCTR


Registration number
ACTRN12623000199617
Ethics application status
Approved
Date submitted
5/02/2023
Date registered
24/02/2023
Date last updated
28/10/2024
Date data sharing statement initially provided
24/02/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Nutrition for gestational diabetes, a pilot study.
Scientific title
Gestational diabetes management: feasibility of a personalised nutrition intervention
Secondary ID [1] 308916 0
Nil known
Universal Trial Number (UTN)
U1111-1287-9759
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Gestational diabetes mellitus 328916 0
Pregnancy 328917 0
Condition category
Condition code
Metabolic and Endocrine 325910 325910 0 0
Diabetes
Diet and Nutrition 325911 325911 0 0
Other diet and nutrition disorders
Reproductive Health and Childbirth 325972 325972 0 0
Fetal medicine and complications of pregnancy

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Women who express interest in the study, either via online advertisement or from the face to face hospital GDM clinic (described below), will be provided with either an electronic or hard copy of the participant information sheet. Women will then consent to complete an online screening form using REDCap to assess eligibility.

For women recruited online, they will be provided with either an electronic or hard copy of the participant information sheet. Following eligibility using REDCap, the research assistant will contact the participant to go over the study, answer any questions, and book them in for their baseline, face to face clinic visit.

Following diagnosis of GDM at 24-28 weeks’ gestation, women will attend their routine group counselling session 1-2 days following (usually 28-29 weeks’ gestation). At this visit, a research assistant will enrol eligible and consenting women. Participants will be asked to complete a short questionnaire (demographic information and pregnancy history) and baseline measures: 1) non-fasting blood test; 2) current height and weight; 2) blood pressure; and 4) a 24-hour dietary recall (24 HDR) interview using a web-based dietary assessment tool ASA24®. After this, women will be randomised to one of two groups: control/standard care or intervention.

Up to two days after enrolment, a study dietitian will follow up with women randomised to the intervention group via telephone or zoom where they will receive a 30-minute individual counselling session with the study dietitian incorporating behaviour change techniques. The study dietitian will review the 24 HDR and develop tailored advice for each participant (15 minutes). They will receive an individual counselling session via telephone or zoom with the dietitian on how to increase intake of whole fruits, vegetables, and nuts, modify cooking oils, and decrease intake of ultra-processed foods. This session will be a complement rather than a replacement of the group counselling sessions. Women who ask for clarification on material covered in the standard GDM counselling session will be referred to the diabetes educator to avoid confounding. The study dietitian will maintain regular contact with intervention participants via telephone, SMS, or email to ensure compliance with the dietary intervention. Following the individual counselling session, the study dietitian will contact participants on a fortnightly basis. Compliance will be measured by self-report; the proportion of women meeting personalised targets for fruit, vegetable and nuts, modifications to cooking oils, and reduction in servings of ultra-processed foods will be determined from the number of current daily servings reported.

To aid in behaviour change, within the counselling session, the study dietitian (who will be trained and supported by a health psychologist), will incorporate the use of behaviour change techniques drawn from the Behaviour Change Technique Taxonomy (15 minutes). The behaviour change technique clusters to be used in this session include shaping knowledge, antecedents, goals and planning, repetition and substitution, and social support. During this coaching session, the dietitian will use the behaviour change technique clusters of feedback and monitoring, shaping knowledge, antecedents, goals and planning, repetition and substitution, and social support. Specifically, the dietitian will: 1) review goals, action plans, antecedents, dietary behaviours (including habit reversals and substitutions) and outcomes; 2) assist women to revise their goals, action plans, dietary behaviours and restructure their environment if needed; 3) provide feedback on diet behaviours; 4) provide further practical advice on how to improve diet, and 5) provide support by recognising and complimenting positive changes, normalising any difficulties associated with dietary change or behaviour relapse and encouraging women to continue in their efforts. Discussion will also include identifying people within their network that can be emotional and/or practical supports in their efforts to establish a healthy diet.
Women allocated to the intervention group will receive health coaching advice again at 32-34 weeks' gestation to strengthen uptake.

A trained phlebotomist will collect a maternal venous blood sample (up to 14 ml) according to standard SOP for venepuncture, at baseline and at the end of the intervention period. For women who choose not to have a blood sample, the study researcher will follow up on reasons for this (self reported, no specific checklist). Feasibility will be assessed by proportion of women having the blood sample taken, and a written description for common reasons among women where a sample was not taken.
Intervention code [1] 325358 0
Lifestyle
Comparator / control treatment
Women randomised to standard care will receive usual nutrition care for GDM, as conducted at their usual hospital of care. This typically includes conventional diet therapy focused on carbohydrate modification, self-blood glucose monitoring, and physical activity (SA Health Guidelines), with follow-up appointments when required. Dietary advice is generally delivered in group setting ~28-29 weeks’ gestation. A certified diabetes educator provides an overview of GDM and instructs women on how to monitor their blood glucose levels at home. Powerpoint presentations may be utilised to support learning, along with advice from a dietitian trained in GDM nutrition care. Follow up session are made to ensure their blood glucose levels are within range—e.g., fasting levels (before breakfast) = 5.0 mmol/L and two-hour post prandial levels =6.7 mmol/L. Women with uncontrolled blood glucose levels may be referred for one on one visits with the dietitian. To complement dietary advice, women are also advised to aim for ~150 minutes per week of moderate physical activity to support healthy pregnancy weight gain. If blood glucose levels cannot be maintained with lifestyle changes, women might be referred to an obstetric physician / endocrinologist to commence pharmacological treatment (insulin). The standard care will complete the same baseline and endline measurements as that of the intervention group, including questions related to behaviour change.
Control group
Active

Outcomes
Primary outcome [1] 333747 0
The primary outcome is study feasibility, including 1) participant recruitment rate, defined as the number of participants recruited and randomised per month. This will be calculated using data from the study enrolment and recruitment database,
Timepoint [1] 333747 0
End of study (~36-38 week's gestation)
Primary outcome [2] 333815 0
2) participant retention rates, calculated as the percentage of randomised participants that were assessed for the primary outcome (i.e. started the study) and included in the analysis of the primary outcome (ie, the number of participants included in the analysis of the primary outcome divided by the number of participants recruited and randomised). This will be calculated using data from the study enrolment and recruitment database,
Timepoint [2] 333815 0
End of study (~36-38 week's gestation)
Primary outcome [3] 333816 0
3) feasibility of the eligibility criteria (consent rate), calculated as the percentage of eligible participants that consented and were randomised (ie, the total number of participants recruited and randomised divided by the number of eligible participants). This will be calculated using data from the study enrolment and recruitment database,
Timepoint [3] 333816 0
End of study (~36-38 week's gestation)
Secondary outcome [1] 418132 0
Feasibility of the additional non-fasting blood measurements. For eligible women who choose not to have a blood sample, the study researcher will follow up on reasons for this (self reported, no specific checklist) and the common reasons among women where a sample was not taken will be reported in the manuscript text. The proportion of women who did not have the blood sample taken will be divided by the total number of participants and reported as a percentage.
Timepoint [1] 418132 0
Baseline (~29-30 weeks' gestation), end of study (~36-38 week's gestation).
Secondary outcome [2] 418421 0
Quantitative feedback regarding the personalisation process and its acceptability:

A dietary feedback text message will be sent to all women, using a scale to respond to the question “how do you rate the relevance of the dietary advice provided to you in the study”: not relevant, somewhat relevant, mostly relevant, very relevant. At the end of the study, participants will also be asked to respond to the question: In future studies, how would you prefer to receive your dietary feedback:
• Preference for information on how to obtain positive results Y/N, or Preference on how to prevent negative consequences. Y/N
• Preference for seeking advice when the respondent requests Y/N, or Preference to receive advice on the same fixed moment. Y/N
• Preference for short and direct information Y/N or Preference for detailed information that includes explanations about why the advice is good for the respondent.
Timepoint [2] 418421 0
End of study (~36-38 week's gestation).
Secondary outcome [3] 418435 0
Health outcome measures include 1) food group intake. That is, the proportion of women meeting personalised targets for fruit, vegetable and nuts, cooking oils, and ultra-processed foods. This information is gathered from an electronic checklist that the participants respond to at the beginning and end of study.
Timepoint [3] 418435 0
Baseline (~29-30 weeks' gestation), end of study (~36-38 week's gestation).
Secondary outcome [4] 418436 0
Health outcome measures include 2) metabolic health markers (triglycerides) and will be reported as mean (standard deviation). This will be done using a non-fasting blood sample taken by a trained phlebotomist.
Timepoint [4] 418436 0
Baseline (~29-30 weeks' gestation), end of study (~36-38 week's gestation).
Secondary outcome [5] 418889 0
Health outcome measures include 2) metabolic health markers (glucose) and will be reported as mean (standard deviation). This will be done using a non-fasting blood sample taken by a trained phlebotomist.
Timepoint [5] 418889 0
Baseline (~29-30 weeks' gestation), end of study (~36-38 week's gestation).

Eligibility
Key inclusion criteria
Diagnosed with GDM by a 75 g Oral Glucose Tolerance Test (OGTT) between 24-28 weeks’ gestation, using the International Association of Diabetes in Pregnancy Study Groups (IADPSG)/Australasian Diabetes in Pregnancy Society (ADIPS) diagnostic criteria.
Minimum age
18 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Overt diabetes in pregnancy.
2. Type 1 diabetes
3. T2DM
4. Poorly controlled hypothyroidism
5. Graves’ Disease
6. Multiple pregnancy
7. Vegetarian/vegan diet
8. Antibiotic use within the past 3 months
9. Steroid use
10. Currently taking antipsychotic medication.
11. Currently taking lipid lowering drugs
12. If women commence any lipid altering drugs during the intervention phase of the study, they will revert to standard care and will remain in the study with outcome data collected for inclusion in the intention to treat analysis.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled 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
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Process evaluation measures will include participant recruitment and retention rates; feasibility of the eligibility criteria (numbers/reasons of women who screen, enrol); and qualitative feedback regarding the personalisation process and its acceptability. The feasibility outcomes will be reported descriptively and narratively.

Health outcome measures include dietary intake and metabolic health markers. These measures will be reported as mean (standard deviation) for continuous outcomes and raw count (%) for categorical outcomes. Regression modelling will be used to examine relationships between exposure variables (dietary intake) and secondary (anthropometry, metabolic health) outcomes.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
SA

Funding & Sponsors
Funding source category [1] 313126 0
Government body
Name [1] 313126 0
National Health and Medical Research Council (NHMRC)
Country [1] 313126 0
Australia
Primary sponsor type
University
Name
The University of Adelaide
Address
4 North Terrace
Adelaide, 5005, SA
Australia
Country
Australia
Secondary sponsor category [1] 314826 0
None
Name [1] 314826 0
Address [1] 314826 0
Country [1] 314826 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 312371 0
Women's and Children's Health Network Human Research Ethics Committee
Ethics committee address [1] 312371 0
Ethics committee country [1] 312371 0
Australia
Date submitted for ethics approval [1] 312371 0
18/01/2023
Approval date [1] 312371 0
20/03/2023
Ethics approval number [1] 312371 0
2023/HRE00008

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 124418 0
Dr Jessica Grieger
Address 124418 0
The University of Adelaide
Adelaide Health and Medical Sciences Building
Corner of North Terrace & George Street
North Terrace, Adelaide, 5000
SA, Australia
Country 124418 0
Australia
Phone 124418 0
+61 8 8313 7697
Fax 124418 0
Email 124418 0
Contact person for public queries
Name 124419 0
Jessica Grieger
Address 124419 0
The University of Adelaide
Adelaide Health and Medical Sciences Building
Corner of North Terrace & George Street
North Terrace, Adelaide, 5000
SA, Australia
Country 124419 0
Australia
Phone 124419 0
+61 8 8313 7697
Fax 124419 0
Email 124419 0
Contact person for scientific queries
Name 124420 0
Jessica Grieger
Address 124420 0
The University of Adelaide
Adelaide Health and Medical Sciences Building
Corner of North Terrace & George Street
North Terrace, Adelaide, 5000
SA, Australia
Country 124420 0
Australia
Phone 124420 0
+61 8 8313 7697
Fax 124420 0
Email 124420 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


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.