CHICAGO (AP) _ Doctors should not be required to discuss fetal pain with women seeking abortions because fetuses likely can't feel pain until late in pregnancy, according to a review critics say hardly settles the contentious topic.
Researchers at the University of California, San Francisco reviewed dozens of studies and medical reports and said the data indicate that fetuses likely are incapable of feeling pain until around the seventh month of pregnancy, when they are about 28 weeks old.
Based on the evidence, discussions of fetal pain for abortions performed before the end of the second trimester should not be mandatory, according to the study appearing in Wednesday's Journal of the American Medical Association.
The review, researchers say, is an attempt to present a comprehensive, objective report on evidence to inform the debate over fetal pain laws aimed at making women think twice before getting abortions.
Critics angrily disputed the findings and claimed the report is biased.
``They have literally stuck their hands into a hornet's nest,'' said Dr. Kanwaljeet Anand, a fetal pain researcher at the University of Arkansas for Medical Sciences, who believes fetuses as young as 20 weeks old feel pain. ``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. This is not the last word _ definitely not.''
Proposed federal legislation would require doctors to provide fetal pain information to women seeking abortions when fetuses are at least 20 weeks old, and to offer women fetal anesthesia at that stage of the pregnancy. A handful of states have enacted similar measures.
The review says medical evidence shows that brain structures involved in feeling pain begin forming earlier but likely do not function until around the seventh month, when fetuses are about 28 weeks old.
Some scientists say younger fetuses show pain by moving away from a stimulus, but that likely is a reflex action and not an indication that they are actually feeling pain, said UCSF obstetric anesthesiologist Dr. Mark Rosen, the study's senior author.
Offering fetal pain relief in the fifth or sixth month, when brains are too immature to feel pain, is misguided and might result in unacceptable health risks to women, the authors said.
Dr. Nancy Chescheir, chairman of obstetrics and gynecology at Vanderbilt University and a board director at the Society of Maternal-Fetal Medicine, said the report ``will help to develop some consensus'' on when fetuses feel pain. ``To date, there hasn't been any.''
The measure pending in Congress would affect about 18,000 U.S. abortions a year performed in the fifth month of pregnancy or later, said Douglas Johnson, legislative director of the National Right to Life Committee. He said the review is slanted.
Dr. Catherine DeAngelis, JAMA's editor-in-chief, said the decision to publish the review was not politically motivated.
JAMA does not publish ``politically motivated science. We publish data-based, evidence-based science,'' she said.
Rosen said researchers ``tried to review the literature in an unbiased fashion. This was a multidisciplinary effort by experts on anesthesia, neuroanatomy, obstetrics and neonatal development.''
When doctors operate on fetuses to correct defects before birth, general anesthesia is given to the mother primarily to immobilize the fetus and to make the uterus relax. Anesthesia during fetal surgery increases the mother's risks for breathing problems and bleeding from a relaxed uterus, the researchers said.
Rosen said those risks are medically acceptable when the goal is to save the fetus but there is not enough evidence to show any benefit from fetus-directed anesthesia during an abortion.
Administering anesthesia directly to the fetus is also sometimes done but generally to reduce the release of potentially harmful fetal stress hormones, Rosen said. There is little research on its effects.
But Anand said the study's authors excluded or minimized evidence suggesting fetal pain sensation begins in the second trimester and wrongly assume that fetuses' brains sense pain in the same way as adult brains.
While Anand has testified as an expert witness for the government in court cases opposing some late-term abortions, he said he is not anti-abortion and that his views are based on years of fetal pain research.