The 40th anniversary in October this year of the passing of the UK Abortion Act is certain to be marked by attempts to reopen the debate about lowering the upper limit for legal terminations. In a special report in this week's BMJ, journalist Jonathan Gornall examines current arguments for reform.
Any challenge to the upper limit of 24 weeks poses big questions about viability, infant suffering, and the capabilities of neonatal care, writes Gornall - and the danger is that this vital debate is taking place increasingly on emotional rather than scientific grounds.
The ProLife Alliance can take much of the credit for having put abortion back on the public and political agenda over the past decade. The organisation was set up in 1996 as a political party to show "the reality of abortion" and was also behind the ultimately failed attempt in 2003 by Joanna Jepson, a trainee vicar, to have police prosecute two doctors over the late abortion of a fetus with a cleft lip and palate.
Now the alliance has turned its attention away from pictures of dead babies to 4D ultrasound images of live ones in the womb.
The technique was pioneered by Stuart Campbell, head of obstetrics and gynaecology at St George's Hospital, London, who is convinced that his 4D images have undermined the validity of the current time limit for abortion.
But Maria Fitzgerald, professor of developmental neurobiology at University College London and scientific director of the WellChild Pain Research Centre says it is wrong to suggest that the fetus might feel pain in the same way as the born child.
But whether or not fetuses feel pain in the same way as infants, another debate is raging over the survival rates of extremely premature infants and the viability of such survivors.
The British Medical Association believes that the 1967 Abortion Act is a humane piece of legislation, and guidelines recently issued by the Nuffield Council on Bioethics suggest that below 22 weeks, "no baby should be resuscitated." Its proposals came as a disappointment to anti-abortion campaigners.
Most recently, the anti-choice lobby has been emphasising the risk to the physical or mental health of women who have abortions.
If the upper limit for abortion is reduced this year, it seems it will be in response to public opinion informed not by scientific and medical realities but by sentimental pictures - and on the back of occasionally misleading polls, writes Gornall.
A Conservative MP is currently promoting a bill to reduce the abortion limit to 20 weeks, and this seems to represent the anti-choice lobby's best chance of lowering the upper limit in the act's anniversary year. But there is concern that her position seems to reflect the ethical and medical confusion that threatens to overwhelm clear debate in the year ahead.
Forty years after the law was changed, the pro-choice lobby ask why shouldn't abortion be treated like any other operation, where the doctor gives one the information to make an informed choice about whether to undergo surgery? They believe we need to move the focus from the fetus to the woman, Gornall concludes.