Glucose measured in maternal plasma after 5 hours of fasting during pregnancy
This test checks your blood sugar level in your baby’s placenta after a 5-hour fast to help assess how well your baby’s pancreas is working.
["This test helps monitor your baby’s risk for diabetes during pregnancy."]
Key facts at a glance
- LOINC
- 42631-2
- Short code
- Glucose 5h p Lac PO Ur-mCnc
- Synonyms
- Glucose 5h p Lac PO Ur-mCnc
- Category
- glucose
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 70
- Ref high
- 100
- Critical range
- 50 N/A – 400 N/A
- Fasting
- true
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82947
- SNOMED
- 260395008
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why is this test done?
Your healthcare provider may order this test if you have risk factors for gestational diabetes, such as obesity, a family history of diabetes, or being over 25 years old. It helps ensure your baby’s health and reduces the risk of complications during pregnancy.
What does the test involve?
You’ll fast for 5 hours before the test. A small sample of blood is taken from your placenta (or sometimes from your umbilical cord) to measure your glucose levels. This is usually done during a prenatal visit or a special procedure called a glucose tolerance test.
What should you expect?
The test is quick and painless. You may feel a slight pinch when the blood sample is taken. Afterward, you can resume normal activities unless your provider gives specific instructions.
What do the results mean?
Results help determine if your baby’s pancreas is functioning normally. High levels may indicate a higher risk for diabetes in your baby, prompting further testing or monitoring.
Reference range
Fasting: 70-100 mg/dLN/A
Fasting for 8-12 hours required. Water is permitted. Avoid chewing gum and smoking before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: This test is critical for identifying gestational diabetes risks early. Elevated glucose levels can lead to complications for both mother and baby, including macrosomia (large baby) or preeclampsia. Early detection allows for interventions like diet, exercise, or medication to manage blood sugar levels safely.
Frequently asked questions
Why is fasting required for this test?
How is the blood sample taken from the placenta?
Can I eat or drink anything before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy