Alpplac2cfrserpl

Published: July 31, 2026Updated: August 16, 2026

This blood test measures the ratio of placental alkaline phosphatase to total alkaline phosphatase, used to assess placental health during pregnancy.

Quick summary

{"Measures placental alkaline phosphatase as a percentage of total ALP","Helps monitor placental function and pregnancy health","Requires a simple blood draw","Results are expressed as a ratio or percentage","Abnormal results may indicate pregnancy complications"}

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

Key facts at a glance

LOINC: 71363-6
Short code: ALP Plac 2 CFr SerPl
Synonyms: ALP Plac 2 CFr SerPl
Category: chemistry
Sample: serum
Container: Red-top tube (SST)
Units: not specified
Ref low: 0
Ref high: 0.05
Fasting: false
Population: adult
Sex: all
Age range: 18–65 years
CPT: 84075
SNOMED: 27550007
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 is this test?

The placental alkaline phosphatase ratio test measures how much of the total alkaline phosphatase (ALP) in your blood comes from the placenta. Alkaline phosphatase is an enzyme found in various tissues in your body, including your liver, bones, intestines, and during pregnancy, the placenta. This test calculates the percentage or ratio of placental alkaline phosphatase (PLAP) relative to the total ALP in your blood.

Why is this test performed?

This test is primarily used to monitor placental health during pregnancy. The placenta provides essential nutrients and oxygen to your developing baby. By measuring placental alkaline phosphatase levels, healthcare providers can assess how well the placenta is functioning. This test may be used to detect placental insufficiency, monitor high-risk pregnancies, or evaluate certain pregnancy-related conditions.

How is the test done?

A healthcare professional will draw a small blood sample from a vein in your arm. The blood is collected into a tube and sent to a laboratory for analysis. The laboratory measures both placental alkaline phosphatase and total alkaline phosphatase, then calculates the ratio or percentage. The procedure is quick and similar to other routine blood tests.

What do the results mean?

During a healthy pregnancy, placental alkaline phosphatase levels naturally increase as the placenta grows. Your healthcare provider will interpret your results based on your gestational age and overall health. Abnormal results—whether too high or too low—may warrant further investigation to ensure the health of both you and your baby.

Are there any risks?

The risks associated with this test are minimal and similar to those of routine blood draws. You may experience slight bruising, soreness, or bleeding at the puncture site. In rare cases, fainting or infection may occur. These risks are generally minor and resolve quickly.

Reference range

0.0-0.05not specified

Specimen: serum

No fasting or special preparation required. Note pregnancy status (placental ALP fraction rises in pregnancy).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Do I need to fast before this test?

Fasting is typically not required for this test. However, always follow your healthcare provider's specific instructions, as they may request fasting based on other tests being performed simultaneously.

When during pregnancy is this test performed?

This test is usually performed during the second and third trimesters of pregnancy when placental alkaline phosphatase production is at its highest. Your healthcare provider will determine the appropriate timing based on your specific clinical situation.

Is this test dangerous for my baby?

No, this test only requires a blood sample from the mother. It poses no risk to the developing baby.

What happens if my results are abnormal?

An abnormal result does not necessarily indicate a problem. Your healthcare provider will consider your results along with other test findings, ultrasound results, and your overall clinical condition to determine if any additional monitoring or intervention is needed.

Can men or non-pregnant women have this test?

While placental alkaline phosphatase is primarily produced during pregnancy, small amounts may be present in certain conditions. This test is typically used in pregnancy monitoring but may occasionally be ordered in other clinical situations as determined by your healthcare provider.

Sources

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