Four month old foetus. Image of a human foetus at sixteen weeks of age (in side view) surrounded by its mother's womb and the membraneous amniotic sac. The foetal head is at right, with the face seen in profile and the eye dark. The torso reveals a ribcage, while the umbilical cord is spiral in shape. At this age the foetus appears completely human. Fingers and toes have formed and the skin will be covered with a fine hair (lanugo), while eyebrows and hair on the head develop. The crown-rump length (sitting height) at 16 weeks is about 14 centimetres and the body weight is about 200 grams.