Fetal Antibody Titration (Serum)
This test measures the level of antibodies in your baby’s blood to check for exposure to certain infections during pregnancy.
["It helps determine if your baby may need additional protection against infections like rubella, cytomegalovirus, or toxoplasmosis."]
Key facts at a glance
- LOINC
- 25333-6
- Short code
- CAMPF
- Synonyms
- C fetus Ab Titr Ser
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum collection tube (no anticoagulant) or serum separator tube (SST, tiger-top). Avoid hemolyzed, lipemic, or icteric specimens.
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Serum antibody detection by complement fixation, microagglutination, or indirect immunofluorescence assay (IFA). Titer determined by serial dilution of serum and reporting the highest dilution showing positive reactivity.
- CPT
- 86622
- SNOMED
- 12211004
- Specimen volume
- 2-5 mL of whole blood (yields approximately 1-2 mL of serum)
- Stability
- Serum stable for 7 days at 2-8°C (refrigerated); for extended storage, freeze at -20°C or below for up to 6 months. Avoid repeated freeze-thaw cycles. Transport to reference laboratory on cold packs.
- Hemolysis max
- 2
- Lipemia max
- 2
- Icterus max
- 2
- TAT
- 48–168 hours
- Order
- routine
Why This Test Is Done
Doctors may recommend this test if you have been exposed to specific infections (like rubella or toxoplasmosis) during pregnancy, or if you have certain medical conditions that increase your risk of infection. It helps ensure your baby’s safety by identifying if antibodies are present to protect against these risks.
What to Expect During the Test
A small blood sample is taken from your baby’s heel or umbilical cord after birth. The sample is sent to a lab where antibodies are tested using an immunoassay method to measure their concentration.
What the Results Mean
Results are typically reported as a ratio or titer level, indicating the strength of your baby’s antibody response. High levels may mean the baby received protection from antibodies passed through the placenta.
Common Conditions Monitored
This test is often used to monitor babies born to mothers who had infections like rubella, cytomegalovirus (CMV), or toxoplasmosis. It helps assess whether the baby’s immune system received adequate protection.
Reference range
Titer <1:2: Negative (no significant antibodies detected); Titer 1:2–1:4: Equivocal/Borderline; Titer ≥1:8: Positive (indicates prior exposure or active infection)N/A
No fasting required. No special patient preparation needed. Sample should be collected prior to initiation of antimicrobial therapy when possible to avoid false-negative results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
How soon will I get my baby’s test results?
What does a positive or negative result mean for my baby’s health?
Can I prevent my baby from needing 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