What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 11947-9: Head circumference/Abdominal circumference derived by US

Name: LOINC Code 11947-9: Head circumference/Abdominal circumference derived by US
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:22.974Z

11947-9 is a LOINC code used to identify Head circumference/Abdominal circumference derived by US in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Head circumference/Abdominal circumference. It is commonly used with the system or sample type ^Fetus.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Head circumference/Abdominal circumference. It is commonly used with the system or sample type ^Fetus.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation
Method: US.derived

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Head circumference/Abdominal circumference derived by US
Head circumference/Abdominal circumference
Abd; Abdo; Abdomen; AC; der US; Echoencephalogram; Echoencephalography; Echography; Fetal; Girth; Gyn; Gynecology; HC; Length Ratio; OB; ObGyn; OBSTERICAL; OBSTERICAL.ULTRASOUND; Obstetrical; Obstetrics; Point in time; QNT; Quan; Quant; Quantitative; Random; Sonogram; Sonograph; Sonography; ULS; Ultrasound

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Head circumference/Abdominal circumference derived by USHC/AC der USHead circumference/Abdominal circumferenceOB.USLenRtoPt^Fetus

Frequently asked questions

Code details

Code11947-9

SystemLOINC

Display nameHead circumference/Abdominal circumference derived by US

DescriptionHead circumference/Abdominal circumference

Short nameHC/AC der US

ComponentHead circumference/Abdominal circumference

PropertyLenRto

TimingPt

System (specimen)^Fetus

ScaleQn

MethodUS.derived

ClassOB.US

Example unitsratio

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0j-a

Last changed2.73

Part names

Head circumference/Abdominal circumferenceLenRtoPt^FetusQnUS.derivedLength RatioPoint in time (spot)Ultrasound.derived

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.