Condition category
Pregnancy and Childbirth
Date applied
13/09/2019
Date assigned
07/10/2019
Last edited
03/10/2019
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
During pregnancy blood sugar levels become higher than normal in one eighth of Irish women. The term gestational diabetes is used to describe this elevation in sugar levels. Women with gestational diabetes, compared to women without gestational diabetes, have a higher risk of pregnancy complications such as preeclampsia in the mother and baby shoulder damage during delivery. Keeping the blood sugar levels in the normal range decreases the risk of pregnancy complications.

We wish to compare the two methods for screening for gestational diabetes.
- The oral glucose tolerance test is one of the methods. This involves an overnight fast of at least twelve hours, blood sampling before ingestion of 75 grams of glucose and blood sampling one and two hours afterwards.
- The glucose challenge test is the other method. No fast is involved in this test - a sample of blood is taken one hour after ingestion of 50 grams of glucose.

Who can participate?
All pregnant women aged 18-45

What does the study involve?
We will allocate randomly at least 600 women to undergo screening for gestational diabetes by either the oral glucose tolerance test or by the glucose challenge test. Women who chose not to participate in this study will continue to have standard obstetric care in Midland Regional Hospital Mullingar which involves a 75 gram oral glucose tolerance test if a risk factor for gestational diabetes is present.

We will determine glucose levels in women who agree to participate in this study by taking a blood sample upon study entry and again 21 weeks later (1-2 weeks before the estimated date of delivery). We will assess also quality of life and cost as well as the health of mothers and children.

What are the possible benefits and risks of participating?
Participants will not directly benefit by involvement in this research study. The knowledge gained from this study will inform management of other pregnant women in the future. If the one test is found to be preferable this will benefit the obstetric service offered in the MRHM.

The only potential risk is from the discomfort of venepuncture and possible bruising from the venepuncture site but this is non- serious and transient as is evident from their use in routine care. The national standard of care, currently offered by this obstetric service, will still be provided for every participant.

Where is the study run from?
Midland Regional Hospital Mullingar Hospital, Ireland

When is the study starting and how long is it expected to run for?
October 2013 to November 2015

Who is funding the study?
Midlands Regional Hospital Mullingar Diabetes Account

Who is the main contact?
Dr Tomas Ahern
hamillma@tcd.ie

Trial website

Contact information

Type

Public

Primary contact

Dr Tomas Ahern

ORCID ID

Contact details

Our Lady of Lourdes Hospital
Drogheda
Co. Louth
Drogheda
A92 VW28
Ireland
+353 (0)872079003
hamillma@tcd.ie

Additional identifiers

EudraCT number

Nil known

ClinicalTrials.gov number

Nil known

Protocol/serial number

Nil known

Study information

Scientific title

Screening for gestational diabetes: a randomised clinical trial comparing the glucose challenge test and the oral glucose tolerance test

Acronym

Study hypothesis

Gestational diabetes is a state of hyperglycaemia, which affects 18% of pregnancies and can lead to a plethora of maternal and foetal complications. The risks of GDM can be mitigated by optimising glycaemia.

Although universal screening for GDM is accepted generally as desirable, the best strategy for GDM screening and diagnosis remains to be determined. The American Diabetes Association (ADA) and the International Association of Diabetes and Pregnancy Study (IADPSG) endorse use of the 75 g oral glucose tolerance test (OGTT) for screening. The American College of Obstetrics and Gynaecology (ACOG) on the other hand, recommends screening with the 50 g glucose challenge test (GCT) as part of a two-stage process involving a 100 g oral glucose tolerance test for those with a positive GCT.

The researchers plan to compare these two methods for screening for gestational diabetes. If they find that the glucose challenge test is as good, or is better, than the oral glucose tolerance test at ensuring good pregnancy outcomes, this will lead to a meaningful improvement in how pregnant women are managed in the future.

The hypothesis is that the rate of unfavourable pregnancy outcomes is lower with GCT screening than with OGTT screening.

Ethics approval

Approved 17/09/2013, Research Ethics Committee, Health Service Executive - Midland Area (HSE Area Offices, Arden Road, Tullamore, Co. Offally, Ireland; +353 579359894; paul.marsden@hse.ie), ref: 040913MG

Study design

Single-centre 24-week prospective parallel-arm clinical trial

Primary study design

Interventional

Secondary study design

Randomised parallel trial

Trial setting

Hospitals

Trial type

Screening

Patient information sheet

Not available in web format, please use contact details to request a participant information sheet

Condition

Gestational diabetes

Intervention

The interventions involved in this trial are the two methods of screening for gestational diabetes:
1. The oral glucose tolerance test involves an overnight fast of at least 12 hours, blood sampling before ingestion of 75 g of glucose and blood sampling 1 and 2 hours afterwards. Use of the oral glucose tolerance test is recommended by the American Diabetes Association and by the International Association of Diabetes and Pregnancy Study Group.
2. The glucose challenge test is the other method. No fast is involved. A sample of blood is taken one hour after ingestion of 50 g of glucose. Use of the glucose challenge test is recommended by the American College of Obstetrics and Gynaecology as part of a two-stage process where those with a positive glucose tolerance test go on to have a 100 g oral glucose tolerance test.

The researchers randomly allocate 600 women to undergo screening for gestational diabetes by either the oral glucose tolerance test or by the glucose challenge test. Women who choose not to participate in this study will continue to receive the standard obstetric care in this centre (which involves a 75 g oral glucose tolerance test if a risk factor for gestational diabetes is present.)

The glucose levels in women who agree to participate in this study will be taken upon study entry and again 21 weeks later (1-2 weeks before the estimated date of delivery).

Intervention type

Other

Phase

Drug names

Primary outcome measure

Maternal blood glycated haemoglobin level (HbA1c) at 16 and 36 weeks gestation

Secondary outcome measures

1. Maternal quality of life measured using PES scale, DASS, PSSS, EQ5D
2. Cost (attendance for GDM screening, attendance for prenatal visits, number of prenatal visits)
3. Fetal and neonatal parameters (large-for-gestational-age, birth weight> 4 kg, shoulder dystocia, bone fracture, nerve palsy, stillbirth, perinatal death, hypoglycaemia, weight, jaundice, admission to the special care baby unit)
4. Maternal and delivery parameters (gestational hypertension, pre-eclampsia, eclampsia, gestational diabetes, hypoglycaemia, HbA1c >5.6%, receipt of nutritional counselling, use of glucose-lowering therapies, blood pressure, weight gain, induction of labour, caesarean delivery)

Overall trial start date

20/09/2013

Overall trial end date

23/05/2016

Reason abandoned (if study stopped)

Eligibility

Participant inclusion criteria

All pregnant women aged 18-45

Participant type

Patient

Age group

Adult

Gender

Female

Target number of participants

600

Total final enrolment

600

Participant exclusion criteria

1. Previous diagnosis of diabetes
2. Use of insulin
3. HbA1C>6.5%
4. Inability to give informed consent

Recruitment start date

02/10/2013

Recruitment end date

11/11/2015

Locations

Countries of recruitment

Ireland

Trial participating centre

Midland Regional Hospital Mullingar Hospital
Co. Westmeath
Mullingar
N91 NA43
Ireland

Sponsor information

Organisation

Our Lady of Lourdes Hospital

Sponsor details

c/o Dr Tomas Ahern
Drogheda
Co. Louth
Drogheda
A92VW28
Ireland
+353 (0)872079003
hamillma@tcd.ie

Sponsor type

Hospital/treatment centre

Website

Funders

Funder type

Hospital/treatment centre

Funder name

Midlands Regional Hospital Mullingar Diabetes Account

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

The researchers plan to publish their trial results in an international peer-reviewed journal with an emphasis on the areas of obstetrics, maternal health and foetal development.

IPD sharing statement:
The datasets generated during and/or analysed during the current study will be stored in a publically available repository. https://data.mendeley.com/datasets/tdnt9xvmr5/draft?a=fbf623af-8c81-407e-a6fa-ace8ab941c9a
This link will work (and allow you to download the database) for the next three months (as of 01/10/2019)

Intention to publish date

01/10/2019

Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

02/10/2019: Trial’s existence confirmed by Research Ethics Committee, HSE- Midland Area