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Fetal Progesterone Level (Serum or Plasma)

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

This test measures the level of progesterone, a hormone important for pregnancy, in your blood. It helps monitor fetal development and assess risks of complications like preterm labor.

Quick summary

["Progesterone levels help track pregnancy health and identify potential risks early."]

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

Key facts at a glance

LOINC
61189-7
Short code
INR PPP Fetus
Synonyms
INR PPP Fetus
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
coag-tissue-factor-induced-inr
CPT
85610
SNOMED
396252006
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 order this test if you're at risk for preterm labor, experiencing early pregnancy symptoms, or if you have a history of pregnancy complications. It can also be used to evaluate the progress of an early pregnancy or monitor conditions like threatened miscarriage.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for a few hours before the blood draw. Wear comfortable clothing and plan to stay near the testing site for a short time. Avoid smoking or caffeine before the test if instructed.

What Happens During the Test?

A healthcare professional will insert a small needle into a vein in your arm to draw blood. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample will be sent to a lab for analysis.

What Are the Possible Results?

Results are interpreted by your healthcare provider based on your specific situation. Lower than expected levels may indicate risks for pregnancy complications, while higher levels might suggest other health concerns. Your provider will discuss the meaning of your results in the context of your medical history and symptoms.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: plasma

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Fetal Progesterone

Frequently asked questions

What Does This Test Measure?
This test measures the concentration of progesterone in your blood. Progesterone is a hormone produced by the ovaries and placenta that helps maintain pregnancy by preparing the uterus for a growing fetus and supporting early development.
How Might My Results Affect My Pregnancy?
Low progesterone levels may signal risks for preterm labor or other pregnancy complications. High levels might be checked for other conditions, such as ovarian cysts or hormonal imbalances. Your provider will guide you on next steps based on your results.
Is This Test Painful?
The blood draw itself may cause a brief discomfort or slight pain, but it’s generally over quickly. Most people experience minimal or no lasting effects. Always follow your provider’s instructions for post-test care.
  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