The International Association for the Study of Pain published a clinical update on Fetal Pain in June 2006. Their conclusion was that : The available scientific evidence makes it possible, even probable, that fetal pain perception occurs well before late gestation. Those attempting to deny or delay its occurrence must offer conclusive evidence for the absence of fetal pain at given levels of maturity.
A study which findings were published in the journal, Archives of Disease in Childhood - Fetal and Neonatal Edtion, revealed that unborn babies cry within the womb. Ultrasound videos taken of infants within the womb revealed 28-week-old babies crying in response to a noise stimulus.
A report from the Parliamentary Pro-Life Group in the UK published in 2000 found that the unborn foetus is capable of feeling pain from the tenth week of pregnancy. The report of findings by 15 scientists from Britain, Ireland and Australia said that foetuses can experience pain earlier than previously thought. Of the 165,000 abortions carried out in England and Wales each year, about 100,000 are performed at nine weeks or later.
The report, runs counter to evidence presented in an official review by Maria Fitzgerald, Professor of Neurodevelopmental Biology at University College Hospital, London, which was commissioned by the Health Department. Her review, Foetal Pain - An Update of Current Scientific Knowledge, published in May 1995, concluded that there was no evidence that the foetus could feel pain earlier than 26 weeks because its brain and neurological system were not sufficiently developed.
Some scientists, not linked with the Parliamentary Pro-Life Group, questioned Professor Fitzgerald's conclusion.
As reported in The Times February 2000, Nicholas Fisk and Vivette Glover, two of Britain's foremost researchers on foetal pain, say the issue demands examination. Professor Fisk, Queen Charlotte's Maternity Hospital, Chiswick, London measured levels of cortisol, a stress hormone, in foetuses from which blood samples were taken in the womb.
He found that the level rose sharply as the needle was inserted. "This is the first evidence that the human foetus mounts a definable stress response to a potentially painful stimulus," he said.
Advances in surgery mean that many foetuses undergo operations inside the womb without analgesia even though pain relief is routinely given to premature babies of the same gestational age undergoing the procedure after birth.
In 1996 the Rawlinson Commission of Inquiry into Foetal Sentience, UK, discovered that a large, and growing, body of evidence suggested that a baby can feel pain and sensation from 11 weeks of gestation.
On 19 November 1987, the New England Journal of Medicine (Volume 317, Number 21: Pages 1321-1329) printed an special article and concluded :
Numerous lines of evidence suggest that even in the human fetus, pain pathways as well as cortical and subcortical centers necessary for pain perception are well developed late in gestation, and the neurochemical systems now known to be associated with pain transmission and modulation are intact and functional. Physiologic responses to painful stimuli have been well documented in neonates of various gestational ages and are reflected in hormonal, metabolic, and cardiorespiratory changes similar to but greater than those observed in adult subjects. Other responses in newborn infants are suggestive of integrated emotional and behavioral responses to pain and are retained in memory long enough to modify subsequent behavior patterns.