Mary Calvagna, MS
Your doctor should assess your risk for
at your first prenatal visit. If you already have diabetes and you become pregnant, then you do not need to be screened for gestational diabetes.
If you have risk factors for developing gestational diabetes (such as,
obesity, family history for
type 2 diabetes, or previous history of gestational diabetes), your doctor may recommend that you undergo glucose tolerance testing as soon as possible. If your initial test is negative, you will be retested between 24 and 28 weeks of gestation.
If you are at average risk, your doctor will give you a screening test between 24-28 weeks of gestation.
You may not need to be screened if you are at low risk for gestational diabetes. But, to be low risk, you must meet all of the following criteria:
For the 50 gram glucose screening test, you do not need to fast. You are given a drink that contains 50 grams of glucose. One hour later, your blood sugar level is tested.
Doctors use different screening tests and cutoff values to suspect the diagnosis. Generally, these 1 hour values range from 130 mg/dL (7.2 mmol/L) to 140 mg/dL (7.8 mmol/L). If your blood glucose is abnormally high at 1 hour, you will need to take a 3-hour glucose tolerance test to confirm the diagnosis.
Gestational diabetes mellitus (GDM). EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116237/Gestational-diabetes-mellitus-GDM. Updated July 7, 2016. Accessed October 4, 2016.
Screening for gestational diabetes mellitus. The Society of Obstetricians and Gynaecologists of Canada website. Available at:
http://www.sogc.org/guidelines/public/121E-CPG-November2002.pdf. Published November 2002. Accessed September 16, 2015.
What I need to know about gestational diabetes. National Diabetes Information Clearinghouse (NDIC) website. Available at:
http://diabetes.niddk.nih.gov/dm/pubs/gestational/#7. Updated August 2015. Accessed September 16, 2015.
5/7/2014 4/25/2014 DynaMed Plus Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T116237/Gestational-diabetes-mellitus-GDM: Screening and diagnosis of gestational diabetes mellitus. National Guideline Clearinghouse website. Available at: http://www.guideline.gov/syntheses/synthesis.aspx?id=47907. Updated May 2014. Accessed May 7, 2014.
Last reviewed September 2015 by Andrea Chisholm, MD
EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Information Services. All rights reserved.