Human Developmental Biology Resource (HDBR)

Staging Guidelines

Embryo Staging

Embryos are staged following the guidelines in Bullen et al (1994) following using the Carnegie Staging classification system (O'Rahilly and ~Muller 1987). The staging chart we use can be downloaded here.

Fetal Staging

An estimation of fetal development is made using the staging guidelines set out be Hern 1982. A copy of our fetal staging chart can be downloaded here.