Phenotypic screening for fetal hemoglobin and other hemoglobin variants (serum/plasma mass concentration)
This test measures certain types of hemoglobin in your blood to check for genetic conditions that may affect your baby’s red blood cells during pregnancy.
["This screening helps identify potential hemoglobin disorders that could impact fetal health."]
Key facts at a glance
- LOINC
- 64719-8
- Short code
- Father pregnancy ever PhenX
- Synonyms
- Father pregnancy ever PhenX
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Critical range
- 0.5 N/A – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- phenx
- CPT
- 86592
- 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 During Pregnancy
Pregnancy can sometimes involve genetic conditions that alter how your body produces hemoglobin, the protein in red blood cells that carries oxygen. This test helps detect if your baby inherits certain hemoglobin types that may require extra monitoring or treatment.
What to Expect Before the Test
No special preparation is needed. A blood sample will be taken from your arm, similar to a routine blood draw. The lab will analyze the hemoglobin composition in your blood to identify any unusual patterns.
What the Results Mean
Results may show normal fetal hemoglobin levels or indicate the presence of rare hemoglobin variants. These variants can sometimes be linked to conditions like sickle cell trait or thalassemia, which may need further evaluation by your healthcare provider.
Common Conditions This Test Helps Detect
This screening is particularly useful for identifying hemoglobinopathies, which are genetic disorders affecting hemoglobin production. It may also help rule out conditions that could influence fetal development or require specialized care.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Fetal hemoglobin screening
Frequently asked questions
What does a positive result mean for my baby?
Will this test affect my pregnancy?
Can I prepare for this test differently if I have a history of hemoglobin disorders?
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 17, 2026. · Read our editorial policy