Niketa and Haresh Mehta had sought permission to abort their 25-week-old foetus, which has a heart block. (PTI)
New Delhi, Aug. 6: Research has thrown up mounting evidence for and some against the idea that a 25-week-old foetus can experience pain, even intense pain, polarising the medical community.
Bombay High Court rejected earlier this week a plea by a couple to abort a 25-week-old foetus. The ruling has sparked a debate on abortion, which, in some countries, has often touched on the issue of foetal perception of pain.
At 25 weeks, a normal foetus would weigh more than 750 grams and virtually all the nerve pathways designed to carry pain signals are in place. But what exactly foetuses perceive is still under a polarised medical debate.
Doctors who conduct amniocentesis — a diagnostic procedure involving extraction of amniotic fluid from the womb during a pregnancy — have often found that if the probe accidentally touches the foetus, it displays a startle response.
The evidence is undeniable. Even a 20-week foetus is likely to feel pain, and excruciating pain, said Kanwaljeet Anand, an Indian-born paediatrician and foetal pain specialist at the University of Arkansas for Medical Sciences, Little Rock, Arkansas, US.
Anand, who has conducted research on foetal perceptions of pain for more than two decades, believes foetuses experience more intense pain than the pain felt by infants, children or adults.
This is because pain transmission pathways have developed in the foetus, but not the pain modulation pathways that are not effective until six weeks after birth.
But some doctors argue that the brain of a 25-week-old foetus is not yet ready to interpret — and thus experience —pain the way babies or even adults do.
Pain perception requires conscious recognition or awareness of a noxious stimulus, a team of US-based doctors had written in the Journal of the American Medical Association three years ago.
The reflex movements observed in foetuses stimulated by touch do not prove the existence of foetal pain because they can be elicited by non-painful stimuli and occur without conscious processing in the brain, the US team said. Foetal awareness of noxious stimuli requires special connections within the brain that begin appearing only between 23 and 30 weeks, the review said.
At 20 weeks, the physical apparatus for pain signal transmission is in place, said Shashi Wadhwa, a senior professor of anatomy at the All India Institute of Medical Sciences, New Delhi.
But pain has physical and emotional components. Specific regions of the brain that allow a sensation to be interpreted as something that hurts are not yet fully developed at 20 weeks, said Wadhwa, who had during the mid-1990s conducted experiments on ducks to study foetal development and perceptions.
It is still unclear whether a foetus interprets a sensation as unpleasant, she said.
Anand concedes that not all doctors are convinced about foetal pain. There is more than enough evidence now. But no one is as blind as someone who doesnt want to see.
He said any procedure on a foetus — a medical procedure or abortion — after 20 weeks should take into account the possibility of causing foetal pain and provide anaesthesia to the foetus.
One way would be to introduce an anaesthetic into the amniotic fluid from where it would be absorbed by the foetus.