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 11823-2: Fetal Head Diameter.biparietal/Diameter.occipital derived by US

Name: LOINC Code 11823-2: Fetal Head Diameter.biparietal/Diameter.occipital derived by US
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:22.973Z

11823-2 is a LOINC code used to identify Fetal Head Diameter.biparietal/Diameter.occipital 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 Diameter.biparietal/Diameter.occipital. It is commonly used with the system or sample type Head^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 Diameter.biparietal/Diameter.occipital. It is commonly used with the system or sample type Head^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 Head Diameter.biparietal/Diameter.occipital derived by US
Diameter.biparietal/Diameter.occipital
Ratio of biparietal diameter (short axis) to occipito-frontal diameter (long axis) x 100
BPD; BPD/Diam.occipital; Brain; Cephalic index; CI; Cranial; Cranium; der US; DIA; Diam; Echoencephalogram; Echoencephalography; Echography; Fetal; Gyn; Gynecology; Intracranial; Length Ratio; OB; ObGyn; OBSTERICAL; OBSTERICAL.ULTRASOUND; Obstetrical; Obstetrics; OFD; Point in time; QNT; Quan; Quant; Quantitative; Random; Skull; 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 Head Diameter.biparietal/Diameter.occipital derived by USFet BPD/OFD der USDiameter.biparietal/Diameter.occipitalOB.USLenRtoPtHead^fetus

Frequently asked questions

Code details

Code11823-2

SystemLOINC

Display nameFetal Head Diameter.biparietal/Diameter.occipital derived by US

DescriptionDiameter.biparietal/Diameter.occipital

Short nameFet BPD/OFD der US

ComponentDiameter.biparietal/Diameter.occipital

PropertyLenRto

TimingPt

System (specimen)Head^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

Diameter.biparietal/Diameter.occipitalLenRtoPtHead^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.