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7-Dehydrocholesterol, Amniotic Fluid — Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

Measures 7-dehydrocholesterol in amniotic fluid to help evaluate possible fetal cholesterol synthesis disorders, including Smith-Lemli-Opitz syndrome.

Quick summary

["This prenatal test helps assess whether a fetus may have a disorder that affects cholesterol synthesis."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
48610-0
Short code
7-DHC Amn-mCnc
Synonyms
7-DHC Amn-mCnc
Category
lipid
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

What is this test?

This test measures the amount of 7-dehydrocholesterol, a substance involved in cholesterol production, in amniotic fluid. It may be used when a pregnancy has findings that raise concern for a fetal cholesterol metabolism disorder.

Why might I need this test?

The test may be considered when ultrasound findings, family history, or other prenatal evaluation suggest Smith-Lemli-Opitz syndrome or another condition that affects cholesterol synthesis. It is interpreted together with the pregnancy evaluation and other diagnostic tests.

How is the test performed?

A clinician collects a small amount of amniotic fluid through a procedure called amniocentesis. The laboratory then measures the 7-dehydrocholesterol concentration in the sample.

How do I prepare for the test?

There is no separate laboratory preparation for this measurement. Follow your clinician's instructions for amniocentesis, including any guidance about timing, positioning, or bladder emptying.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated 7-dehydrocholesterol concentration may indicate reduced cholesterol synthesis and can support a diagnosis of Smith-Lemli-Opitz syndrome. Results should be interpreted by a specialist and confirmed or supported with genetic testing when appropriate.

Short name

7-Dehydrocholesterol (Amniotic Fluid)

Frequently asked questions

What does 7-dehydrocholesterol measure?
It measures the concentration of a cholesterol precursor in amniotic fluid. The result can help evaluate certain fetal disorders of cholesterol synthesis.
How is the amniotic fluid obtained?
A trained clinician performs amniocentesis to collect the sample. Your clinician will explain the procedure, its limitations, and any associated risks before it is performed.
Does one result confirm a diagnosis?
Not by itself. The result is reviewed with ultrasound findings, the pregnancy history, and other testing, and genetic evaluation may be needed for confirmation.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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