"Twenty-five years ago, when Kanwaljeet Anand was a medical resident in a neonatal intensive care unit, his tiny patients, many of them preterm infants, were often wheeled out of the ward and into an operating room. He soon learned what to expect on their return. The babies came back in terrible shape: their skin was gray, their breathing shallow, their pulses weak. Anand spent hours stabilizing their vital signs, increasing their oxygen supply and administering insulin to balance their blood sugar. “What’s going on in there to make these babies so stressed?” Anand wondered. Breaking with hospital practice, he wrangled permission to follow his patients into the O.R. “That’s when I discovered that the babies were not getting anesthesia,” he recalled recently. Infants undergoing major surgery were receiving only a paralytic to keep them still. Anand’s encounter with this practice occurred at John Radcliffe Hospital in Oxford, England, but it was common almost everywhere. Doctors were convinced that newborns’ nervous systems were too immature to sense pain, and that the dangers of anesthesia exceeded any potential benefits. Anand resolved to find out if this was true. In a series of clinical trials, he demonstrated that operations performed under minimal or no anesthesia produced a “massive stress response” in newborn babies, releasing a flood of fight-or-flight hormones like adrenaline and cortisol. Potent anesthesia, he found, could significantly reduce this reaction. Babies who were put under during an operation had lower stress-hormone levels, more stable breathing and blood-sugar readings and fewer postoperative complications. Anesthesia even made them more likely to survive. Anand showed that when pain relief was provided during and after heart operations on newborns, the mortality rate dropped from around 25 percent to less than 10 percent. These were extraordinary results, and they helped change the way medicine is practiced. Today, adequate pain relief for even the youngest infants is the standard of care, and the treatment that so concerned Anand two decades ago would now be considered a violation of medical ethics. But Anand was not through with making observations. As NICU technology improved, the preterm infants he cared for grew younger and younger — with gestational ages of 24 weeks, 23, 22 — and he noticed that even the most premature babies grimaced when pricked by a needle. “So I said to myself, Could it be that this pain system is developed and functional before the baby is born?”"