Skip to content

Prenatal Maternal Age Phenotypic Index (Serum)

Published: August 9, 2026Updated: August 17, 2026

This test measures a calculated index related to maternal age during pregnancy, often used to assess potential risks associated with advanced maternal age. It evaluates factors that may influence pregnancy outcomes.

Quick summary

["This test helps evaluate maternal age-related pregnancy risks through a specialized calculation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
64721-4
Short code
Father pregnancy age PhenX
Synonyms
Father pregnancy age 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

What This Test Measures

The test involves analyzing serum samples to derive a composite score that integrates multiple physiological and biochemical markers. These markers reflect how maternal age may impact fetal development and pregnancy health.

Why It’s Done

Healthcare providers may order this test for women of advanced maternal age (typically 35 years or older) to identify potential risks such as chromosomal abnormalities, gestational diabetes, or preeclampsia. It’s not a standalone diagnostic test but part of a broader evaluation.

How It’s Performed

A blood sample is drawn from your arm and sent to a lab. The serum portion is processed to calculate the phenotypic index using specialized algorithms that account for age-specific biomarkers.

What to Expect Before the Test

No special preparation is needed, but inform your healthcare provider if you’re on any medications or have conditions that might affect blood results. Wear comfortable clothing for the blood draw.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Prenatal Age Assessment

Frequently asked questions

A higher index may signal increased risks, prompting additional screening or monitoring. A lower index might suggest lower risk but isn’t definitive. Results are interpreted alongside clinical findings and patient history.
This test does not provide a direct diagnosis but helps guide further prenatal care, such as genetic testing or closer monitoring of pregnancy complications.
How long will I need to wait for results?
Results are typically available within 1–3 business days, depending on lab processing times. Follow up with your healthcare provider to discuss findings and next steps.
Can I fast before this test?
No fasting is required, as this is a serum-based test unrelated to glucose or lipid levels. However, always confirm with your provider if you have questions about medication timing.
  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 17, 2026. · Read our editorial policy