"IF THE NOTION that newborns are incapable of feeling pain was once widespread among doctors, a comparable assumption about fetuses was even more entrenched. Nicholas Fisk is a fetal-medicine specialist and director of the University of Queensland Center for Clinical Research in Australia. For years, he says, “I would be doing a procedure to a fetus, and the mother would ask me, ‘Does my baby feel pain?’ The traditional, knee-jerk reaction was, ‘No, of course not.’” But research in Fisk’s laboratory (then at Imperial College in London) was making him uneasy about that answer. It showed that fetuses as young as 18 weeks react to an invasive procedure with a spike in stress hormones and a shunting of blood flow toward the brain — a strategy, also seen in infants and adults, to protect a vital organ from threat. Then Fisk carried out a study that closely resembled Anand’s pioneering research, using fetuses rather than newborns as his subjects. He selected 45 fetuses that required a potentially painful blood transfusion, giving one-third of them an injection of the potent painkiller fentanyl. As with Anand’s experiments, the results were striking: in fetuses that received the analgesic, the production of stress hormones was halved, and the pattern of blood flow remained normal. Fisk says he believes that his findings provide suggestive evidence of fetal pain — perhaps the best evidence we’ll get. Pain, he notes, is a subjective phenomenon; in adults and older children, doctors measure it by asking patients to describe what they feel. (“On a scale of 0 to 10, how would you rate your current level of pain?”) To be certain that his fetal patients feel pain, Fisk says, “I would need one of them to come up to me at the age of 6 or 7 and say, ‘Excuse me, Doctor, that bloody hurt, what you did to me!’ ” In the absence of such first-person testimony, he concludes, it’s “better to err on the safe side” and assume that the fetus can feel pain starting around 20 to 24 weeks."