Pain Transmission in the Neonate 
Tom Grissom, MD Medical Director, Advanced Pain Centers of Alaska 

The study of preterm infants has helped us understand pain in fetal development.  These preterm infants have the same anatomy and physiology with regards to the nervous system and pain signal transmission.  Since the fetus is incapable of verbal communication other markers for fetal responses to pain are utilized.    

Fetal Pain: The Evidence - doctorsonfetalpain.org

Fetal Pain: The Evidence The eleven points below summarize the substantial medical and scientific evidence that unborn children can feel pain by 20 weeks after fertilization.