Crown-rump length

Ultrasound measurement used to estimate gestational age in early pregnancy.

Last updated 5 November 2026

Crown-rump length, or CRL, measures a human embryo or fetus from the top of its head to the bottom of its buttocks. This measurement, usually taken via ultrasound, helps doctors estimate how far along a pregnancy is.

Quick Facts

Average gestational period: 280 days (9 months and 6 days)

Facts from the source article.

More in Obstetrics

Decidua Delayed cord clamping (DCC)Doppler fetal monitor Early postnatal hospital discharge Echogenic intracardiac focus Etiology, Concept and Prophylaxis of Childbed Fever Ferguson reflex Fetal head Fetal heart rate Fetal heart tones Final maturation induction Obstetrics

Sources

Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.

Wikipedia: Crown-rump length (CC BY-SA 4.0).
Word definitions: the Codexery glossary, each quoted from its Wikipedia article.

Spotted an error? Know more?

Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced

Comments

Loading…

Open in the interactive codex →