August 23, 2005
Fetal pain unlikely before third trimester-study
CHICAGO (Reuters) - A human fetus is unlikely to feel pain
before the third trimester, when consciousness begins to form,
researchers said on Tuesday in a report that could fuel debate
over proposed U.S. abortion legislation.
Even if a fetus feels pain, doctors may not be able to
anesthetize it without endangering the mother's health,
including during an abortion, the researchers wrote in the
Journal of the American Medical Association.
some U.S. states would require doctors to inform women seeking
abortions after the 22nd week of gestation that their fetus
feels pain and offer to anesthetize the fetus.
Supporters of the legislation say that when a fetus
displays a withdrawal reflex or hormonal stress response, that
is evidence of fetal pain. But the researchers at the
University of California, San Francisco, questioned that view,
saying the responses may be automatic and not signs of
Drawing on findings from thousands of medical-journal
articles on the subject of fetal pain and related topics, the
report's author, Susan Lee, wrote that "pain is a subjective
sensory and emotional experience that requires the presence of
Consciousness is created by brain connections between the
thalamus and the cerebral cortex, and those do not begin to
develop before the 23rd week and possibly not before the 30th
week of gestation. The human gestation period is 38 weeks from
"Conscious perception of pain does not begin before the
third trimester," Lee wrote. In the United States, only 1.4
percent of abortions are performed at or after 21 weeks
gestational age, the report said.
Anesthesia is used in some surgeries where the fetus is
operated on inside the womb, but it is not done to address
fetal pain, Lee wrote. It is designed to relax the uterus,
immobilize the fetus, or ease stress if surgical complications
In addition, the dose needed to anesthetize a fetus might
endanger the mother by slowing her breathing excessively, the
report said, adding new anesthetizing techniques would have to
be developed to address fetal pain, if it exists.
Dr. Wendy Chavkin of Physicians for Reproductive Choice,
and Health, commenting on the report, said its conclusions
affirmed what other experts have found, and denounced the
proposed legislation concerning fetal pain.
"These laws have nothing to do with pain or pain reduction,
but are clearly intended to stigmatize abortion, the women who
have abortions and the doctors who provide them," she said.