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Trial registered on ANZCTR


Trial ID
ACTRN12615000290594
Ethics application status
Approved
Date submitted
3/03/2015
Date registered
27/03/2015
Date last updated
23/11/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
Gestational Diabetes Mellitus Trial of Diagnostic Detection Thresholds (GEMS)
Scientific title
Gestational Diabetes Mellitus Trial of diagnostic detection thresholds comparing International Association of Diabetes in Pregnancy Study Groups (IADPSG) criteria with New Zealand criteria in women with gestational diabetes for reducing the risk of the infant being large for gestational age.
Secondary ID [1] 281734 0
Nil
Universal Trial Number (UTN)
Nil
Trial acronym
GEMS
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Gestational Diabetes Mellitus 288037 0
Condition category
Condition code
Reproductive Health and Childbirth 288413 288413 0 0
Fetal medicine and complications of pregnancy
Metabolic and Endocrine 294762 294762 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
IADPSG Diagnostic Criteria Group classified as normal or GDM based on their 75g OGTT results:
- Normal by IADPSG criteria (fasting plasma glucose <5.1 mmol/L, AND 1 hour <10.0 mmol/L, AND 2 hour <8.5 mmol/L).
- GDM by IADPSG diagnostic criteria (fasting plasma glucose >/=5.1 mmol/L, OR 1 hour >/=10.0mmol/L, OR 2 hour >/=8.5 mmol/L).
The OGTT undertaken at a single occasion only as in routine antenatal care.
Intervention code [1] 286270 0
Diagnosis / Prognosis
Comparator / control treatment
Current Diagnostic Criteria Group classified as normal OR GDM based on their 75g OGTT results:
-Normal by current criteria (fasting plasma glucose <5.5 mmol/L, AND 2 hour <9.0 mmol/L).
- GDM by current criteria (fasting plasma glucose >/=5.5mmol/L, AND 2 hour >/=9.0 mmol/L).
The OGTT undertaken at a single occasion only as in routine antenatal care.
Control group
Active

Outcomes
Primary outcome [1] 294413 0
Large for gestational age infant (birth weight >90th centile)
Timepoint [1] 294413 0
At birth
Secondary outcome [1] 313238 0
For the woman: pre-eclampsia assessed from patient medical records.
Timepoint [1] 313238 0
At primary hospital discharge after birth
Secondary outcome [2] 313239 0
For the woman: induction of labour assessed from patient medical records.
Timepoint [2] 313239 0
At primary hospital discharge after birth
Secondary outcome [3] 313240 0
For the woman: mode of birth assessed from patient medical records.
Timepoint [3] 313240 0
At primary hospital discharge after birth
Secondary outcome [4] 313241 0
For the woman: gestational weight gain
Timepoint [4] 313241 0
At primary hospital discharge after birth
Secondary outcome [5] 313242 0
For the woman: postpartum haemorrhage >/=500mls assessed from patient medical records.
Timepoint [5] 313242 0
At primary hospital discharge after birth
Secondary outcome [6] 313316 0
For the woman: puereral sepsis requiring antibiotics assessed from patient medical records.
Timepoint [6] 313316 0
At primary discharge after birth
Secondary outcome [7] 313317 0
For the woman: serious health outcomes up to the time of primary hospital discharge assessed from patient medical records.
This composite outcome of serious health problems for the women as defined by Rumbold et al. New England Journal of Medicine 2006;354(17):1796-806.
Timepoint [7] 313317 0
At primary hospital discharge after birth
Secondary outcome [8] 313318 0
For the woman: breastfeeding (yes/no) assessed from patient medical records.
Timepoint [8] 313318 0
At primary hospital discharge after birth
Secondary outcome [9] 313319 0
For the infant: a composite of serious health outcomes (defined as perinatal death, birth trauma, nerve palsy, bone fracture, shoulder dystocia) assessed from patient medical records.
Timepoint [9] 313319 0
At primary hospital discharge after birth
Secondary outcome [10] 313324 0
For the infant: gestational age at birth collected after birth from the case record.
Timepoint [10] 313324 0
After birth
Secondary outcome [11] 313325 0
For the infant: Apgar score <4 at five minutes after birth
Timepoint [11] 313325 0
At 5 minutes after birth
Secondary outcome [12] 313326 0
For the infant: respiratory support assessed from patient medical records.
Timepoint [12] 313326 0
At primary hospital discharge after birth
Secondary outcome [13] 313327 0
For the infant: hypoglycaemia requiring treatment (defined as blood glucose <2.6 mmol/L
Timepoint [13] 313327 0
At primary hospital discharge after birth
Secondary outcome [14] 313328 0
For the infant: hyperbilirubinaemia requiring phototherapy assessed from patient medical records.
Timepoint [14] 313328 0
At primary hospital discharge after birth
Secondary outcome [15] 313329 0
For the infant: neonatal encephalopathy assessed from patient medical records.
Timepoint [15] 313329 0
At primary hospital discharge after birth
Secondary outcome [16] 313330 0
For the infant: macrosomia (>/=4kg)
Timepoint [16] 313330 0
At primary hospital discharge after birth
Secondary outcome [17] 313331 0
For the infant: small for gestational age (SGA) (birth weight <10th percentile)
Timepoint [17] 313331 0
At primary hospital discharge after birth
Secondary outcome [18] 313332 0
For the infant: fat mass assessed by skinfold measurement taken by trained research staff.
Timepoint [18] 313332 0
At primary hospital discharge after birth

Eligibility
Key inclusion criteria
Women with a singleton pregnancy eligible for testing for GDM at 24 to 34 weeks’ gestation, who give written, informed consent.
Minimum age
No limit
Maximum age
No limit
Gender
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Women with known diabetes mellitus or previously diagnosed GDM.

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation will be concealed. Eligible women will be offered participation in GEMS when considering their options for testing for GDM midpregnancy. They will be provided with the study information by their lead maternity carer (LMC) or the research personnel, counselled about the study and with their consent can be provisionally enrolled in the trial prior to testing for GDM. All consenting women will have a 75g OGTT arranged by their LMC with plasma glucose concentrations determined on fasting, and at 1 and 2 hours. After their OGTT, elible women will be randomised, at a ratio 1:1, using a central computerised system, into two study groups: either the IADPSG Diagnostic Criteria Group or the Current Diagnostic Group.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The central randomisation service will use a randomisation schedule with balanced variable blocks, prepared by an investigator not involved with recruitment or clinical care, using a randomisation table created by computer software. Stratification will be by BMI (<25 and >/=25) and by planned birthing institution.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Safety/efficacy
Statistical methods / analysis
For the primary outcome of LGA, a trial of 9,624 women will be able to show an 18.0% reduction in risk from 12.2% with current New Zealand criteria to 10.0% using the IADPSG criteria (International Association of Diabetes Pregnancy Study Groups Consensus Panel 2010), ('alpha' = 5%, two-tailed, 90% power, 10% loss to follow up), based on HAPO (HAPO Study Cooperative Research Group 2008) and LGA rates from unpublished information in ACHOIS.
The analyses will follow several key steps. Baseline characteristics of all randomised women will be summarised descriptively by study groups. treatment evaluations will use intention-to-treat principle. Statistical tests will be two-sided and maintained at 5% level of significance. Imputation method will be applied to the primary outcome with any missing data. the risks estimates and 95% CIs will be reported using log binomial regression for binary outcomes. Continuous outcomes will be analysed using linear regression.

Recruitment
Recruitment status
Recruiting
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 outside Australia
Country [1] 6692 0
New Zealand
State/province [1] 6692 0

Funding & Sponsors
Funding source category [1] 290829 0
Government body
Name [1] 290829 0
Health Research Council of New Zealand
Address [1] 290829 0
PO Box 5541
Wellesley Street
Auckland
1141
Country [1] 290829 0
New Zealand
Primary sponsor type
University
Name
University of Auckland, Research Office
Address
Faculty of Medical and Health Sciences
The University of Auckland
Private Bag 92019
Auckland 1142
Country
New Zealand
Secondary sponsor category [1] 289519 0
None
Name [1] 289519 0
Address [1] 289519 0
Country [1] 289519 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292451 0
Health & Disability Ethics Committee (HDEC)
Ethics committee address [1] 292451 0
Ministry of Health
C/-MEDSAFE
Level 6
Deloitte House
10 Brandon Street
PO Box 5013
Wellington
6011
Ethics committee country [1] 292451 0
New Zealand
Date submitted for ethics approval [1] 292451 0
Approval date [1] 292451 0
14/11/2014
Ethics approval number [1] 292451 0
13NTB18AM01

Summary
Brief summary
Gestational diabetes (GDM) is a significant health problem affecting one in every 12 pregnant women or over 5,200 women in New Zealand annually. GDM has a major, negative impact on maternal and perinatal health with lifelong consequences. There is no consensus as to the degree of high blood glucose needed for the diagnosis of GDM or when treatment will be beneficial, due to a lack of high quality evidence.
Our randomised trial compares important health outcomes for mothers and babies of treating women with GDM by the current criteria used in New Zealand with newly proposed criteria, that use a lower threshold and will diagnose more women as having GDM. Our results will show which diagnostic criteria is best for the health of mothers and babies, which is more cost-effective, and so provide the necessary information to guide clinical practice and policy in New Zealand, with global relevance.
Trial website
http://www.liggins.auckland.ac.nz/en/for/thecommunity/gems-study.html
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 36854 0
Prof Caroline Crowther
Address 36854 0
The Liggins Institute
Private Bag 92019
Auckland
1142
Country 36854 0
New Zealand
Phone 36854 0
+64 9 923 6011
Fax 36854 0
Email 36854 0
c.crowther@auckland.ac.nz
Contact person for public queries
Name 36855 0
Mrs Debbie Samuel
Address 36855 0
The Liggins Institute
Private Bag 92019
Auckland
1142
Country 36855 0
New Zealand
Phone 36855 0
+64 9 923 1356
Fax 36855 0
Email 36855 0
d.samuel@auckland.ac.nz
Contact person for scientific queries
Name 36856 0
Prof Caroline Crowther
Address 36856 0
The Liggins Institute
Private Bag 92019
Auckland
1142
Country 36856 0
New Zealand
Phone 36856 0
+64 9 923 6011
Fax 36856 0
Email 36856 0
c.crowther@auckland.ac.nz