Week 8 - fetus begins producing brain waves.
Week 10 - heart almost completely developed.
Week 12 - vocal cords completely formed. Fetus can cry and feel pain and smell.
Week 13 - the fetus has acquired more reflexes: touching the palms makes the fingers close, touching the soles of the feet makes the toes curl down and touching the eyelids makes the eye muscles clench
week 14 - spontaneous movement begins. The fetus controls his/her movement. Begins to make sucking motions with mouth.
Week 16 - fetus can suck its thumb, and likes to play with the umbilical cord.
Week 18 - fetus can blink, grasp, and open and close its mouth.
Week 20 - fetus can hear, learn, and react to stimuli. Starts to swallow amniotic fluid.
Week 22 - fetus reacts more to sound now.
Week 23 - 15% chance of survival if born.
Week 24 - all components of eyes developed. Fetus has hand and footprints. 56% chance of survival.
Week 25 - 75% chance of survival.
Week 26 - fetus can inhale and exhale. Fetus has sense of taste. % of survival if born.