Carnegie Stage 9


N17   N17   N17   N509
46 XY   46 XY   46 XY   46 XY


Carnegie Stage 9 Definition


Age is approximately 26 postovulatory days

Length is approximately 1.4 - 2.5mm

External Features Include: the head fold is present. Neural folds may be apposed but are not yet fused at any point. No visible pharyngeal arch.

O'Rahilly R and Muller F [1987] Developmental Stages in Human Embryos. Carnegie Institute, Washington, Publication no. 637, and O'Rahilly R, Müller F (2010) Developmental stages in human embryos: revised and new measurements. Cells Tissues Organs. 192:73-84. PMID: 20185898.