WEDNESDAY, Aug. 24 (HealthDay News) — A controversial new research article questioning whether early-term fetuses feel pain has triggered a heated debate on how the research might influence the flash-point realm of abortion politics.

But companies a neuroscientist who helped write the paper, published Wednesday, said there’s no doubt about the conclusion: Humans only feel pain if they have a properly functioning brain, and fetuses in the early stages of development don’t.

“The circuitry is not there,” at least in the first 20 weeks, said Dr. Henry Ralston, a professor of anatomy and neuroscience at the University of California, San Francisco. “Without the connections, the sensation can’t take place.”

The report, a review of known research by four doctors and a researcher at UCSF, goes even further: In examining the effectiveness of giving anesthesia to a fetus for therapuetic procedures or abortion, the researchers concluded that fetal perception of pain is unlikely before the third trimester, at 29 to 30 weeks.

Other doctors disagree, however, as do anti-abortion activists who criticized the findings, which appear in the Aug. 24/31 issue of the Journal of the American Medical Association.

Dr. K. S. Anand, a pediatrician at the University of Arkansas for Medical Sciences, told The New York Times, “There is circumstantial evidence to suggest that pain occurs in the fetus.”

Anand said premature babies only 23 or 24 weeks old cry when their heels are pricked for blood tests and become conditioned to cry when someone nears their feet.

“In the first trimester, there is very likely no pain perception,” Anand said. “By the second trimester, all bets are off, and I would argue that in the absence of absolute proof we should give the fetus the benefit of the doubt if we are going to call ourselves compassionate and humane physicians.”

The study is also raising eyebrows, according to a Philadelphia Inquirer report, because one of its authors is the head of an abortion clinic. Her affiliation was not disclosed in the study, nor was that of the lead author, a medical student who once worked for an abortion-rights organization, the newspaper said.

The researcher, UCSF obstetrician-gynecologist Eleanor A. Drey, is medical director of the abortion clinic at San Francisco General Hospital. She told the Inquirer: “We thought it was critical to include an expert in abortion among the authors. I think my presence … should not serve to politicize a scholarly report.”

JAMA editor-in-chief Catherine D. DeAngelis told the newspaper she had been unaware of that.

“This is the first I’ve heard about it,” she said. “We ask them to reveal any conflict of interest. I would have published” the disclosure if it had been made.

The issue of fetal pain, once fairly obscure, has taken an increasingly prominent position in the public consciousness in recent months. More than a dozen state legislatures — including those in New York and California — have debated whether to require doctors to tell women getting abortions about the potential pain felt by fetuses during the procedures. The proposed laws would require doctors to offer anesthesia for the fetus.

Arkansas, Georgia and Minnesota have already passed such laws.

And Congress is considering whether to require doctors to provide anesthesia to fetuses in all cases of abortion after 22 weeks of gestational age. (The new study noted that only 1.2 percent of abortions in the United States are performed at or after 21 weeks.)

Ralston said he and his colleagues launched their study, an analysis of previous research, to provide some perspective on the debate.

The researchers examined studies that looked at feelings of fetal pain before the age of 30 weeks. They found that whi