This is a week of crucial wiring when the placenta and umbilical cord hook up to Mom. The vital organs including the brain, spinal cord, heart, kidneys, liver, and stomach also start to form. With your child's biggest growth spurt until puberty, the embryo more than doubles in size from .16 to .44 inches. The legs and arms extend and grow from the torso and the heart divides into right and left chambers. The forebrain also divides into two hemispheres.
Finite features including eyelids, ears, hair, fingers, and toes start to take shape.
But since the baby still has plenty of room in the uterus, you won't feel these movements for several more weeks. About the size and shape of a medium shrimp, week ten marks the end of the embryonic period and the embryo becomes a fetus with all vital organs and weighs in at about .18 ounces. The neck develops and the head rises up from the chest. It may be possible for curious parents to tell if they have a boy or girl. The small intestine starts functioning, relaxes and contracts to push substances out.