Fetal Kidney Function: Estimated Glomerular Filtration Rate (eGFR) from Amniotic Fluid
This test measures how well the fetal kidneys are filtering waste from amniotic fluid, using a simplified version of the glomerular filtration rate (eGFR) calculation.
["Assesses fetal kidney health by estimating how efficiently waste is removed from amniotic fluid."]
Key facts at a glance
- LOINC
- 11843-0
- Short code
- Fet Kidney Diam.long.mean Est from GA
- Synonyms
- Fet Kidney Diam.long.mean Est from GA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- estimated-from-gestational-age
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters for Fetal Health
Measuring fetal kidney function is important because the kidneys play a critical role in regulating fluid balance and removing waste products from the amniotic fluid. This test helps healthcare providers monitor fetal health during pregnancy, especially in cases where there may be concerns about kidney development or function.
How the Test Works
The test uses a mathematical model (similar to adult eGFR calculations) applied to amniotic fluid creatinine levels to estimate how well the fetal kidneys are filtering waste. Amniotic fluid is collected through a procedure called amniocentesis, where a small amount is taken from the amniotic sac.
What to Expect Before the Test
Before the test, you’ll undergo an amniocentesis procedure under ultrasound guidance. A small needle is inserted into the amniotic sac to collect a small sample of amniotic fluid. This is generally done between 15 and 20 weeks of pregnancy. You may experience mild cramping, but it is usually not painful.
What to Expect During the Test
After the sample is collected, the fluid is sent to a lab for analysis. The lab measures creatinine levels, which are then used to calculate the estimated glomerular filtration rate (eGFR) for the fetus. Results are typically available within a few days.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low fetal eGFR may indicate potential kidney developmental issues or other underlying conditions affecting fetal health. While not a definitive diagnosis, it can prompt further evaluation, such as additional imaging or genetic testing, if abnormalities are detected. Early monitoring helps guide prenatal care decisions.
Short name
Amniotic Fluid eGFR (Fetal Kidney Function)
Frequently asked questions
What does a low or high fetal kidney function result mean?
How often is this test performed during pregnancy?
Is there any risk associated with 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