Impact on pregnancy outcomes when changing diagnostic criteria for gestational diabetes in Sweden

ISRCTN ISRCTN41918550
DOI https://doi.org/10.1186/ISRCTN41918550
Secondary identifying numbers OLL-597601
Submission date
27/11/2017
Registration date
15/12/2017
Last edited
09/07/2024
Recruitment status
No longer recruiting
Overall study status
Ongoing
Condition category
Pregnancy and Childbirth
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Gestational diabetes mellitus (GDM) is high blood sugar that develops during pregnancy. In June 2015, the Swedish National Board of Health reviewed the evidence on the current Swedish and WHO GDM criteria and recommended adoption of the new, stricter WHO diagnostic criteria for what is considered GDM. GDM is currently being treated differently in different hospitals/regions and the care is not equal. It is unknown if the change of the diagnostic criteria will lead to any benefits in Sweden. The new criteria mean a major change in the number of pregnant women who gets diagnosed (estimated a triple increase based on studies in other countries). The CDC4G study is a randomized national multicenter study to evaluate the Swedish National Board of Health's new recommendation for gestational diabetes mellitus (GDM) diagnostic criteria in Sweden. The new diagnostic criteria will be compared to the old criterions used in Sweden. The aim of this study is to examine if treating women with GDM defined by the new criteria will reduce risks of adverse pregnancy outcomes in the Swedish population.

Who can participate?
Pregnant woman in the maternity hospitals.

What does the study involve?
Participating hospitals are randomly allocated to when they switch from the pre-existing Swedish diagnostic criteria for GDM to the WHO 2013 criteria for GDM to the 3 point OGTT with fasting, one hour and/or two hour diagnostic thresholds. Participants are followed up to assess if their babies are large for their gestation age, if they develop hypertension, pre-eclampsia or any other complications at labour.

What are the possible benefits and risks of participating?
The expected outcome is a significant reduction in the proportion of large children and complications related to this during childbirth. Follow-up of mothers, children and their long-term health will be performed through the national health and quality records.
The results of the study are expected to be of great significance for the clinics that treats pregnant women with diabetes. Hopefully it will also lead to a more equal care for when it comes to GDM and for the future pregnant individual, no matter where in Sweden they might live.

Where is the study run from?
This study is being run by the University Hospital Örebro (Sweden) and takes place in hospitals in Sweden.

When is the study starting and how long is it expected to run for?
October 2015 to December 2025

Who is funding the study?
Region Örebro County (Sweden)

Who is the main contact?
Dr Helena Backman

Study website

Contact information

Dr Helena Backman
Scientific

Dept of Obstetrics and Gynecology
University Hospital Örebro
Örebro
70185
Sweden

ORCiD logoORCID ID 0000-0002-2691-7525

Study information

Study designNational multicenter unblinded interventional study with a stepped wedge randomized controlled design
Primary study designInterventional
Secondary study designCluster randomised trial
Study setting(s)Hospital
Study typeDiagnostic
Participant information sheet No participant information sheet available.
Scientific titleImpact of Changing Diagnostic criteria for Gestional diabetes in Sweden - a national stepped wedge randomized controlled trial
Study acronymCDC4G
Study objectives1. Treating women with GDM defined by the new criteria will reduce risks of adverse pregnancy outcomes in the Swedish population.
2. the new criteria will be cost effective. Even though there will be more costs in obstetrics, reduced costs will be seen in neonatal care and probably later on in primary health care.
Ethics approval(s)The Ethical Committee in Uppsala County, 2016/12/07, ref: Dnr2016/487
Health condition(s) or problem(s) studiedGestational diabetes mellitus
InterventionThe intervention is the switch from the pre-existing Swedish diagnostic criteria to the WHO 2013 criteria for GDM to the 3 point OGTT with fasting, 1 hour and/or 2 hour diagnostic thresholds of ≥5.1, ≥10.0, ≥8.5 mmol/l. This stepped wedge randomised controlled study design allows each participating center (cluster) to be their own controls before and after randomization. All eligible women from the participating centres are randomised for starting time to the new regime. Randomisation is done through a RCT module from the Pregnancy Register.
Intervention typeOther
Primary outcome measureLarge for Gestational Age (LGA) is measured as the weight of the baby will be measured at time of birth.
Secondary outcome measuresCurrent secondary outcome measures as of 28/02/2019 in accordance with approved ethical protocol from 07/12/2016:
1. Composite of severe adverse outcomes (stillbirth, neonatal death, Erbs palsy, metabolic acidosis defined as pH <7.05 and BE >12 mmol/l in umbilical artery or pH <7.0 in umbilical artery, Apgar score <4 at 5 minutes, HIE I-III, intracranial haemorrhage, neonatal convulsions, meconium aspiration syndrome, mechanical ventilation)
2. 5-Min Apgar score <7
3. Fractured clavicle
4. Blood glucose in the infants
5. Prematurity <37 weeks
6. NICU admission yes/no
7. NICU days
8. Small for Gestational Age
9. Health economic outcome
10. Incremental Cost Effectiveness Ratio
11. Hypoglycaemia needing IV therapy
12. Phototherapy
13. Blood glucose in the infants

Maternal outcomes:
1. Hypertension, Pre-eclampsia-defined is measured using blood pressure and proteinuria at labour and/or discharge
2. Shoulder dystocia is measured using pregnancy quality register (Shoulder dystocia ICD O660) at labour and/or discharge
3. Perineal trauma-3 and 4 degree measured using pregnancy quality register (Perineal trauma ICD O70) at labour and/or discharge
4. Induction of labour is measured using medical records at labour
5. Breastfeeding at hospital discharge
6. Emergency C-section is measured using medical records at labour and/or discharge
7. Elective C-section is measured using medical records at labour and/or discharge
8. Instrumental delivery is recorded using medical records at labour and/or discharge
9. Length of maternal postnatal stay is recorded using medical records at discharge


Previous secondary outcome measures:
1. Hypertension, Pre-eclampsia-defined is measured using blood pressure and proteinuria at labour and/or discharge
2. Shoulder dystocia is measured using pregnancy quality register (Shoulder dystocia ICD O660) at labour and/or discharge
3. Perineal trauma-3 and 4 degree measured using pregnancy quality register (Perineal trauma ICD O70) at labour and/or discharge
4. Induction of labour is measured using medical records at labour
5. Breastfeeding at hospital discharge
6. Emergency C-section is measured using medical records at labour and/or discharge
7. Elective C-section is measured using medical records at labour and/or discharge
8. Instrumental delivery is recorded using medical records at labour and/or discharge
9. Length of maternal postnatal stay is recorded using medical records at discharge
Overall study start date01/10/2015
Completion date31/12/2025

Eligibility

Participant type(s)Patient
Age groupAdult
SexFemale
Target number of participants12 clusters, total sample size of 71 500 pregnant women (35750 before change and 35750 after change of the new GDM criteria).
Key inclusion criteriaAll pregnant women in the participating hospitals and their uptake regions.
Key exclusion criteriaPreexisting diabetes mellitus.
Date of first enrolment01/01/2018
Date of final enrolment31/12/2018

Locations

Countries of recruitment

  • Sweden

Study participating centres

University Hospital Örebro
Örebro
701 85
Sweden
Sahlgrenska University Hospital
Västra Götaland County
Gothenburg
41685
Sweden
Falun Regional Hospital
Dalarna County
Falun
79185
Sweden
Uppsala academy Hospital
Uppsala county
Uppsala
75375
Sweden
Västerås Hospital
Västmanland County
Västerås
72187
Sweden
Serafen Maternal Health Care Unit
Stockholm County
Stockholm
10535
Sweden
Gotland Hopsital
Gotland County
Gotland
62266
Sweden
Skåne University Hospital
Skåne county
Lund
22242
Sweden
Skåne University Hospital
Malmö
21428
Sweden
Kristianstad Hospital
J A Hedlunds väg 5
Kristianstad
291 33
Sweden
Varberg Hospital
Träslövsvägen 68
Varberg
43281
Sweden
Kungsbacka Hospital
Tölö vägen
Kungsbacka
43480
Sweden

Sponsor information

Region Örebro County
Hospital/treatment centre

Box 161
Örebro
70185
Sweden

Website www.regionorebolan.se
ROR logo "ROR" https://ror.org/00maqj547

Funders

Funder type

Government

Region Örebro County

No information available

Results and Publications

Intention to publish date30/09/2023
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planPlanned publication in a high impact peer reviewed journal. Study protocol will be submitted and published after the last clinic has been randomized fall 2018.
IPD sharing planData can be shared based on the decision of the steering group for CDC4G and according to local regulations and laws.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol article protocol 01/11/2019 06/11/2019 Yes No
Statistical Analysis Plan version 8 28/10/2022 19/12/2022 No No
Statistical Analysis Plan Corrections 12/05/2023 12/05/2023 No No
Results article 08/07/2024 09/07/2024 Yes No

Additional files

ISRCTN41918550_SAP_v8_28Oct2022.pdf
ISRCTN41918550_SAP_Corrections-12May2023.pdf
Corrections

Editorial Notes

09/07/2024: Publication reference added.
12/05/2023: The following changes have been made:
1. SAP file uploaded.
2. The intention to publish date has been changed from 01/12/2019 to 30/09/2023.
3. The Individual participant data (IPD) sharing statement and summary were added.
19/12/2022: The following changes have been made:
1. SAP file uploaded.
2. The scientific contact's details have been changed.
06/11/2019: Publication reference added.
12/03/2019: Internal review.
28/02/2019: The secondary outcome measures were updated.