LOINCActiveObservation

LOINC Code 11978-4: Fetal Abdomen Circumference derived by US

11978-4 is a LOINC code used to identify Fetal Abdomen 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 Perimeter. It is commonly used with the system or sample type Abdomen^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 Perimeter. It is commonly used with the system or sample type Abdomen^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

  • Fetal Abdomen Circumference derived by US
  • Perimeter
  • Derived from separate measures of anterior-posterior and transverse diameters of the abdomen in the transaxial plane.
  • Abd; Abd^Fetus; Abd+Fetus; Abdo; Abdomen+; Abdominal; Abdominal circumference; AC; Circum; Circumference; der US; Echography; Fetal; Gyn; Gynecology; Length; 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

Fetal Abdomen Circumference derived by USFet Abd Circum der USPerimeterOB.USLenPtAbdomen^fetus

Frequently asked questions

Code details

Code11978-4
SystemLOINC
Display nameFetal Abdomen Circumference derived by US
DescriptionPerimeter
Short nameFet Abd Circum der US
ComponentPerimeter
PropertyLen
TimingPt
System (specimen)Abdomen^Fetus
ScaleQn
MethodUS.derived
ClassOB.US
Example unitscm
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0j-a
Last changed2.48

Part names

PerimeterLenPtAbdomen^fetusQnUS.derivedLengthPoint 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.

LOINC Code 11978-4 | HealthAssure