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 81270-1: Gestational age in weeks--at onset of illness

Name: LOINC Code 81270-1: Gestational age in weeks--at onset of illness
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:05.774Z

81270-1 is a LOINC code used to identify Gestational age in weeks--at onset of illness 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^at onset of illness. It is commonly used with the system or sample type ^Patient.

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^at onset of illness. It is commonly used with the system or sample type ^Patient.

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--at onset of illness
Gestational age in W^at onset of illness
The number of weeks gestation at the time of symptom onset for a female patient who was pregnant when her illness began.
GA; GA (weeks); GA in W at onset of illness; Gest; Gestation; Gyn; Gynecology; H+P; H+P.HX; OB; ObGyn; Obstetrics; P prime; 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 weeks--at onset of illnessGA (weeks)--at onset of illnessGestational age in W^at onset of illnessH&P.HXTimePt^Patient

Frequently asked questions

Code details

Code81270-1

SystemLOINC

Display nameGestational age in weeks--at onset of illness

DescriptionGestational age in W^at onset of illness

Short nameGA (weeks)--at onset of illness

ComponentGestational age in W^at onset of illness

PropertyTime

TimingPt

System (specimen)^Patient

ScaleQn

ClassH&P.HX

Example unitswk

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.56

Last changed2.61

Part names

Gestational age in W^at onset of illnessTimePt^PatientQnTime (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.