LOINCActiveObservation

LOINC Code 33066-2: Last menstrual period Estimated from EDD

33066-2 is a LOINC code used to identify Last menstrual period Estimated from EDD 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 Last menstrual period. 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 Last menstrual period. 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
  • Method: Estimated from EDD

What it does not mean

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

Key facts

  • Last menstrual period Estimated from EDD
  • Last menstrual period
  • Est; Est from EDD; Estimated Delivery Date; estimation; Gyn; Gynecology; LMP; OB; ObGyn; OBSTERICAL; OBSTERICAL.ULTRASOUND; Obstetrical; Obstetrics; Past; Point in time; predicted; 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

Last menstrual period Estimated from EDDLMP Est from EDDLast menstrual periodOB.USDatePt^Patient

Frequently asked questions

Code details

Code33066-2
SystemLOINC
Display nameLast menstrual period Estimated from EDD
DescriptionLast menstrual period
Short nameLMP Est from EDD
ComponentLast menstrual period
PropertyDate
TimingPt
System (specimen)^Patient
ScaleQn
MethodEstimated from EDD
ClassOB.US
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.09
Last changed2.50

Part names

Last menstrual periodDatePt^PatientQnEstimated from EDDPoint 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 33066-2 | HealthAssure