The Human Fertilisation and Embryology Bill, currently before Parliament, opens the 1967 Abortion Act up for amendment. The upper limit for socalled 'social abortion' was initially 28 weeks but was lowered to 24 weeks by the 1990 Human Fertilisation and Embryology Act. This change reflected improvements in neonatal care. More premature babies were surviving at lower gestations and under the Infant Life Preservation Act, which is still in force, it remains a crime to abort a baby 'capable of being born alive'.
In written evidence submitted to the House of Commons Science and Technology Committee it was noted that 63% of MPs, nearly two thirds of the public and more than three-quarters of women support a reduction in the 24-week upper age limit. 76% of the public think that aborting a baby at six months is cruel.  A recent poll by Marie Stopes International  found that two thirds of GPs wanted a reduction from 24 weeks. It is therefore somewhat ironic that the BMA remains opposed to a reduction and suggests that the BMA is overly influenced by pro-choice activists and out of touch with grass-roots opinion.
It is not hard to understand why public opinion has changed. Professor Stuart Campbell's highly publicised 4D ultrasound images have shown babies in amazing detail 'walking in the womb' from 12 weeks and stories of babies born alive after failed abortions are increasingly common.  A March 2007 paper  presented data on termination of pregnancy for fetal anomaly from a large population-based cohort of births occurring within a 10-year period from 1995 to 2004 in the West Midlands region of the UK. The authors found that out of a total of 3,189 cases of termination for fetal anomaly, 102 (3.2%) babies were born alive. These live births occurred in 18 out of the 20 maternity units in the West Midlands, and the proportions at different gestations were 14.7% between 16 and 20 weeks, 65.7% between 20 and 24 weeks and 19.6% at or after 24 weeks. Accounts such as these understandably shock the public.
Adding to the growing perception of the humanity of the fetus is the evidence that increasing numbers of babies in the very best neonatal units are surviving below 24 weeks. Individual high profile cases like Manchester's Millie McDonagh,  born after a 22-week pregnancy and the world's most premature baby, and Amillia Taylor, who was born a week younger in the US on 24 October 2006,  are well known.
The EPICure study,  which is used by institutions like the RCOG and BMA to justify not lowering the abortion limit, has been criticised for averaging out survival rates across a variety of UK centres to create the false impression that survival rates of premature babies have not improved. But in the best centres, such as in Minneapolis, Minnesota, 66% of babies born at 23 weeks will survive.  A recent study from University College London,  which made headline news,  confirmed these data in a UK context and showed that the level of disability in premature babies is much less than is commonly believed.
And then there is the question of whether fetuses feel pain. The general public intuitively conclude that they do when they hear that from 16 weeks babies will recoil from a noxious stimulus in the womb and that premature babies born earlier than 24 weeks, if stabbed in the heel with a needle, will withdraw and cry. Some experts claim that it is just a complex reflex we are observing, that babies of this age do not have the proper neurological connections between thalamus and cortex to sense pain. But others, like Professor KJ Anand from the University of Arkansas, who recently addressed MPs in Parliament,  say that this view is based on an outdated understanding of physiology, and that fetuses do have the apparatus to feel pain down to 18 weeks. 
Of course, hormone changes, neurological connections and reflexes do not prove that fetuses feel pain but it seems reasonable to give them the benefit of the doubt. Can any of us imagine telling the mother in a first pregnancy who feels kicks at 19 weeks, or at 17 weeks in a later pregnancy, that her baby is not a sentient being worthy of the utmost respect? And we know that babies are 'alive and kicking' much younger than this when their limbs are too small to be felt. Although we would argue that the value to God of an unborn baby's life is not determined by its capacity for sentience, movement, physiological response or survival outside the womb, but rather by the fact that God knows it,  nonetheless, these considerations are increasingly important to many in the general public and are fuelling a demand for a decrease in the 24 week upper time limit. The country may not yet be ready for major restrictions to abortion, however much we might want to see them. However, the tide of public opinion is turning and a lowering of the upper limit, even to 20 weeks, will save over 3,000 human lives a year.