Fetal Renal Pelvic Diameter Measurement
This test measures the size of the fetal kidney’s upper collecting system (renal pelvis) to assess kidney development and detect potential abnormalities.
["A measurement helps monitor fetal kidney health during pregnancy."]
Key facts at a glance
- LOINC
- 11810-9
- Short code
- Fet Renal pelvis-R Diam US.meas
- Synonyms
- Fet Renal pelvis-R Diam US.meas
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 44
- Ref high
- 147
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- us-measured
- CPT
- 84075
- SNOMED
- 27550007
- 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 Is This Test Done?
Your healthcare provider may recommend this test if you’re at higher risk for fetal kidney issues, such as having a history of kidney problems, diabetes, or hypertension. It’s also used during routine ultrasounds to check for structural abnormalities or growth concerns in the fetus’s urinary system.
How Is the Test Performed?
This test is typically performed during an ultrasound, often between 18 and 24 weeks of pregnancy. A technician uses sound waves to visualize the fetal kidneys and measures the diameter of the renal pelvis. No special preparation is needed.
What Are Possible Findings?
The measurement is compared to expected fetal kidney sizes for gestational age. Abnormal findings may indicate conditions like hydronephrosis (swelling in the kidney) or other developmental issues that may require further evaluation.
What Does It Mean If Results Are Abnormal?
If the renal pelvic diameter is larger than expected, it could signal fluid buildup or blockage in the fetal urinary system. Your provider may recommend additional tests, such as further ultrasounds or genetic counseling, to assess risks and plan next steps.
Reference range
Adult: 44-147 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This measurement is critical for identifying potential fetal kidney disorders early in pregnancy, allowing for timely interventions if needed. It helps ensure both maternal and fetal health by detecting structural or functional issues before they become more serious.
Short name
Fetal Renal Pelvic Diameter
Frequently asked questions
What does a fetal renal pelvic diameter test measure?
Can this test be done at home?
What if my results are outside the expected range?
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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy