8 Week Fetus Size At 8 weeks of pregnancy, your baby is now officially transitioning from an embryo toward the fetal stage and is about the size of a raspberry. The head is still large compared to the body, reflecting rapid brain growth. The brain and spinal cord are developing quickly, and nerve pathways are beginning to form. Facial features are becoming more defined, with the eyes moving closer together, eyelids starting to form, and the upper lip and nose becoming more recognizable. The hear