Last revised by Daniel J Bell on 5 Mar 2021

An embryo (plural: embryos) is the term given to the precursor of a fetus and in humans the embryonic period is usually considered to be between the first (1st) and the eighth (8th) week (eleventh week according to some reports) of development after fertilisation. The term "fetal pole" is sometimes used synonymously with the term embryo. Following this period, the term fetus is used.

History and etymology

The term embryo is derived from the Greek word ἔμβρυον literally meaning "that which grows".

See also

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.