LOINC Code 33158-7: Fetal Head Diameter.biparietal/Diameter.occipital estimated from gestational age by method of Hadlock 1981 (US)

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.estimated from Hadlock 1981

What it does not mean

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

Key facts

• Fetal Head Diameter.biparietal/Diameter.occipital estimated from gestational age by method of Hadlock 1981 (US)
• Diameter.biparietal/Diameter.occipital
• 81; BPD; BPD by GA; BPD predicted from gestational age; BPD/Diam.occipital; Brain; Cephalic index; CI; Cranial; Cranium; DIA; Diam; Echoencephalogram; Echoencephalography; Echography; Est; estimation; Fetal; from GA.Hadlock 1981; Gyn; Gynecology; Intracranial; Length Ratio; OB; ObGyn; OBSTERICAL; OBSTERICAL.ULTRASOUND; Obstetrical; Obstetrics; OFD; Point in time; predicted; QNT; Quan; Quant; Quantitative; Random; Skull; Sonogram; Sonograph; Sonography; ULS; Ultrasound; US+est

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

Frequently asked questions