Check out our newest paper concerning human embryonic staging which is now published in LIFE.

We discoverd that the Carnegie staging system as used for almost a century by embryologists worldwide to stage human embryos in the first 10 weeks of pregnancy has to be used with caution. We observed consistent variations in published data sets, especially regarding embryonic age, varying as large as 11 days between publications. Similarly, for embryonic length, large variations were present.

Based on the reviewed studies, we propose the Carnegie staging system of Prof. Mark Hill (2007) as a gold standard amongst the available data sets in the literature.

We summarized the characteristics per Carnegie stage in a two figures and a table to facilitate the staging of human embryos both in as ex utero.

Thanks to Amsterdam Reproduction and Development Research Institute and Amsterdam UMC for funding our research.