The study, conducted by researchers at the University of California and published in the prestigious Journal of the American Medical Association, argued that foetuses are incapable of feeling pain without the development of consciousness, which is in turn predicated on the creation of connections between the thalamus and the cerebral cortex inside the baby's brain.
These connections are not usually apparent until the 23rd week of pregnancy and may not begin to be made until the 30th week. The study had immediate implications in the political arena, because Congress is considering legislation requiring doctors to inform women seeking abortions after the 22nd week that their foetus feels pain.
About 18,000 women a year would be affected by the new law. A number of individual states have already passed, or at least drafted, similar legislation.
The study's authors, however, said such advice by doctors would not only be scientifically unsound, it could actually be dangerous, because it would encourage patients and medical professionals to anaesthetise foetuses during medical procedures and thus expose them to medical risks for no good reason.
It seemed likely yesterday that Christian fundamentalists and other right-to-life activists pressing for a total ban on abortion would be unimpressed by the new study. At least one expert on foetal pain, Dr Kanwaljeet Anand of the University of Arkansas, raised questions about the study's findings.
"This is going to inflame a lot of scientists who are very, very concerned and are far more knowledgeable in this area than the authors appear to be," he told the Associated Press. "This is not the last word - definitely not." It seemed almost inevitable that anti-abortion activists would accuse the JAMA study of political bias, not least because the researchers are based in the notoriously liberal city of San Francisco.
But that notion was rejected in advance by JAMA's editor-in-chief, Catherine DeAngelis. "Oh please," she said. "If I had a political agenda, I wouldn't pick foetal pain."
Advocates of abortion rights, meanwhile, embraced the study as a powerful argument against the pending legislation in Congress and around the country. "These laws have nothing to do with pain or pain reduction, but are clearly intended to stigmatise abortion, the women who have abortions and the doctors who provide them," said Wendy Chavkin of Physicians for Reproductive Choice and Health. The abortion debate continues to court controversy on both sides of the Atlantic. Before the May 2005 election, Michael Howard suggested lowering the time limit on abortion to 20 weeks, due to advances in medicine and science over the past 15 years.Reuse content