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Trial registered on ANZCTR


Registration number
ACTRN12617000695303
Ethics application status
Approved
Date submitted
4/05/2017
Date registered
15/05/2017
Date last updated
8/01/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
Macrosomia rates in women with diet-controlled gestational diabetes
Scientific title
Macrosomia rates in women with diet-controlled gestational diabetes: a retrospective case-control study
Secondary ID [1] 291856 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Gestational Diabetes 303126 0
Macrosomia 303127 0
Condition category
Condition code
Reproductive Health and Childbirth 302574 302574 0 0
Antenatal care
Reproductive Health and Childbirth 302575 302575 0 0
Complications of newborn
Metabolic and Endocrine 302704 302704 0 0
Diabetes

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
A retrospective case-control study in which all patients with diet-controlled gestational diabetes mellitus (GDM) and singleton pregnancies in a single calendar year (2014) were considered for inclusion in the study. These cases were individually matched to controls without GDM and without type 1 or 2 diabetes. Cases were matched to parity, age and BMI. Controls were selected from the same year and as close as possible to the date of delivery of the case. Primary outcomes were macrosomia, defined by estimated fetal weight >90th centile and >95th centile (separately). Each participant was assessed at a single time point at the birth of their child.
Intervention code [1] 297968 0
Not applicable
Comparator / control treatment
The control group were pregnant women without GDM and without type 1 or 2 diabetes. They were matched according to parity, age and BMI.
Control group
Active

Outcomes
Primary outcome [1] 301988 0
Primary outcomes were macrosomia defined by birth weight >90th centile.
Australian Birth Weight charts were used to classify weights >90th% and >95th% centiles.
Timepoint [1] 301988 0
Weight of infant at birth
Primary outcome [2] 302104 0
birthweight > 95th%
Australian Birth Weight charts were used to classify weights >90th% and >95th% centiles.
Timepoint [2] 302104 0
Weight of infant at birth
Secondary outcome [1] 334447 0
Nil
Timepoint [1] 334447 0
Nil

Eligibility
Key inclusion criteria
We compared a cohort of patients with gestational diabetes managed by dietary measures with a concurrent pregnant control group matched for age, parity and body mass index. All patients with diet-controlled gestational diabetes with singleton pregnancies in a single calendar year in 2014 at the antenatal clinics of the Royal Women's Hospital, Melbourne were considered for inclusion in the study. Patients were identified using data generated from the hospital’s electronic medical record system.

Control patients were selected from those without gestational, type 1 or type 2 diabetes attending for obstetric care at the same hospital. Cases and controls were matched for parity (exactly if possible, otherwise nearest available), age (within mutually exclusive five year groups partitioning the clinic patient age range, 20-24, 25-29, 30-34, 35-39, 40-44 and 45-49) and a similar partitioning of the clinic BMI range (within 5 units, 16-20, 21-25, 26-30, 31-35, 36-40, 41-45, 46-50 and 51-55). Controls were selected from the same calendar year (2014), with a date of delivery as close as possible to the date of delivery of the gestational diabetic case patient.
Minimum age
18 Years
Maximum age
55 Years
Gender
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Patients with multiple pregnancies were excluded, as were patients whose body mass index was unrecorded.

Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Case control
Timing
Retrospective
Statistical methods / analysis
Summary statistics were reported as mean with standard deviation, and/or median, interquartile range (IQR) and range, as appropriate. The closeness of 1:1 matching between cases and controls was assessed as differences within matched pairs of maternal age, BMI and parity. Matched case control gestational diabetes data were analysed with regression models using conditional logistic regression models which returned estimated adjusted odds ratios for the presence of (variously defined) macrosomia associated with maternal gestational diabetes, adjusted for maternal age, BMI, gravidity, parity, baby gender and estimated gestational age (EGA). Data were analysed using Stata version 14.2. No adjustments were made for multiple comparisons.

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)
VIC
Recruitment hospital [1] 8020 0
The Royal Women's Hospital - Parkville
Recruitment postcode(s) [1] 15891 0
3052 - Parkville

Funding & Sponsors
Funding source category [1] 296355 0
Self funded/Unfunded
Name [1] 296355 0
NA
Address [1] 296355 0
NA
Country [1] 296355 0
Primary sponsor type
Hospital
Name
Royal Women's Hospital, Department of Maternal Fetal Medicine and Pregnancy Research Centre
Address
Flemington Road
Parkville 3052
Victoria
Country
Australia
Secondary sponsor category [1] 295287 0
University
Name [1] 295287 0
University of Melbourne
Address [1] 295287 0
Grattan St
Parkville 3052
Victoria
Country [1] 295287 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 297585 0
Royal Women's Human Research Ethics Committee
Ethics committee address [1] 297585 0
Royal Women's Hospital
Flemington Road
Parkville 3052
Victoria
Ethics committee country [1] 297585 0
Australia
Date submitted for ethics approval [1] 297585 0
Approval date [1] 297585 0
21/12/2016
Ethics approval number [1] 297585 0
AQA 16/01

Summary
Brief summary
Background: Current data on the rates of macrosomia in women with gestational diabetes mellitus (GDM) are heterogenous. No study has specifically examined macrosomia rates in women with diet-controlled gestational diabetes.

Aims: To compare the rates of macrosomia between mothers with diet-controlled GDM to mothers without diabetes mellitus.

Methods: A retrospective case-control study in which all patients with diet-controlled GDM and singleton pregnancies in a single calendar year were considered for inclusion in the study. These cases were individually matched to controls without GDM and without type 1 or 2 diabetes. Cases were matched to parity, age and BMI. Controls were selected from the same year and as close as possible to the date of delivery of the case. Primary outcomes were macrosomia, defined by estimated fetal weight >90th centile and >95th centile (separately).

Results: 217 cases were identified with diet-controlled gestational diabetes, out of a total of 7185 births. 15 cases were excluded, leaving 202 cases in total. A total of 16 babies were >90th% and 10 were >95th% in the diet-controlled GDM group. 21 babies were >90th% and 11 were 95th% in the control group.

Conclusions: Our findings suggest that macrosomia is not increased in women with diet-controlled GDM, so women with diet-controlled GDM may not require extra surveillance for fetal growth beyond that of the normal obstetric population. Provided women attend appropriate initial consultations with a diabetes educator and a dietician, are linked in with an experienced maternity centre and care-givers are familiar with blood-glucose targets, serious consideration should be given to new guidelines allowing women with diet-controlled diabetes to have obstetric care within lower risk pathways.

Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 74522 0
Dr Fatima Vally
Address 74522 0
Royal Women's Hospital
Flemington Road
Parkville 3052
Victoria
Country 74522 0
Australia
Phone 74522 0
+61418592864
Fax 74522 0
Email 74522 0
fatima.vally@thewomens.org.au
Contact person for public queries
Name 74523 0
Dr Fatima Vally
Address 74523 0
Royal Women's Hospital
Flemington Road
Parkville 3052
Victoria
Country 74523 0
Australia
Phone 74523 0
+61418592864
Fax 74523 0
Email 74523 0
fatima.vally@thewomens.org.au
Contact person for scientific queries
Name 74524 0
Dr Fatima Vally
Address 74524 0
Royal Women's Hospital
Flemington Road
Parkville 3052
Victoria
Country 74524 0
Australia
Phone 74524 0
+61418592864
Fax 74524 0
Email 74524 0
fatima.vally@thewomens.org.au

No data has been provided for results reporting
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary