Fetus Length: 2.5 cm (1 in). Weight: 20 g. Organogenesis is complete. The heart, with a septum and valves, is beating rhythmically. Facial features are definitely discernible. Extremities have developed. External genitalia are present, but sex is not distinguishable by simple observation. The primitive tail is regressing. Abdomen appears large as the fetal intestine is [...]