Do Fetuses Feel Pain?

Scientists have estimated that pain becomes possible anywhere from 18 to 29 weeks into gestation, maybe later.
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- A new Nebraska law bans abortions after 20 weeks, based on the idea that pain begins then.

- Scientists continue to debate when and how fetuses begin to feel pain.

- Findings could alter the way doctor perform surgery on fetuses, infants and pregnant mothers.

Nebraska recently became the first state to ban abortions after 20 weeks of pregnancy based purely on the idea that fetuses start to feel pain around that time. The law, which adds yet more fuel to an already fiery abortion debate, opened a brimming can of scientific worms.

It turns out that no one really knows what it feels like to be a fetus. Through different interpretations of accumulating evidence, various scientists have estimated that pain becomes possible anywhere from 18 to 29 weeks into gestation, maybe later.

While the debate is essential for doctors who perform fetal surgery, scientists on both sides say their work should not play a role in political matters. Too often, people twist what we know into what they want to believe.

"For decades, the question of fetal pain has been very much overlaid by the implications that it has for abortion," said Kanwaljeet Anand, director of the Pain Neurobiology Laboratory at the University of Tennessee Health Science Center in Memphis.

Anand did much of the formative work suggesting that fetuses truly feel pain and that they feel it remarkably early. "This has nothing to do with abortion," he said.

Stuart Derbyshire, a psychologist and fetal pain expert at the University of Birmingham in the United Kingdom, expressed a stronger view.

"Basing laws on this is really unreasonable," said Derbyshire, who, unlike Anand, thinks pain takes much longer to develop. "Abortion is not a scientific question. It is a moral and political question. To try and make science answer a moral question like that is just wrong. It's cowardice on the part of lawmakers."

A full-term pregnancy lasts about 40 weeks. Premature babies can survive if born after about 22 to 24 weeks, though chances of survival are better after 26 weeks.

One of the first clues that fetuses might feel pain came in the early 1990s, when researchers in England stuck needles into second-trimester fetuses and observed the release of pain-related hormones and nerve-signaling molecules. Before that, doctors thought the fetal nervous system was too undeveloped to feel pain. Even newborns endured surgeries without anesthesia.

"If you or I had that experience," Derbyshire said, "we would wake up and complain loudly."

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