LOINCActiveObservation

LOINC Code 49051-6: Gestational age in weeks

49051-6 is a LOINC code used to identify Gestational age in weeks 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 Gestational age in W. 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 Gestational age in W. 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

What it does not mean

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

Key facts

  • Gestational age in weeks
  • Gestational age in W
  • Fetal; GA; GA (weeks); Gest; Gestation; Gyn; Gynecology; OB; ObGyn; OBSTERICAL; OBSTERICAL.ULTRASOUND; Obstetrical; Obstetrics; Point in time; Prenatal; QNT; Quan; Quant; Quantitative; Random

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

Gestational age in weeksGA (weeks)Gestational age in WOB.USTimePt^Fetus

Frequently asked questions

Code details

Code49051-6
SystemLOINC
Display nameGestational age in weeks
DescriptionGestational age in W
Short nameGA (weeks)
ComponentGestational age in W
PropertyTime
TimingPt
System (specimen)^Fetus
ScaleQn
ClassOB.US
Example unitswk
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.21
Last changed2.73

Part names

Gestational age in WTimePt^FetusQnGestational age in weeksTime (e.g. seconds)Point in time (spot)

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 49051-6 | HealthAssure