I volunteer to play Juliet.
The evidence is clear that a fetus can respond to sights, sounds, and smells, and it can even react to these by producing facial expressions. The evidence is equally clear, however, that these responses are generated by the most primitive parts of the brain, which are unconnected to consciousness, and therefore these actions don’t in any way imply that the fetus is aware. Furthermore, the fetus is deliberately sedated by a series of chemicals produced by the placenta, so even if it had the capacity for consciousness, there is almost no chance that it could ever be conscious in the womb. Consequently, it can’t consciously feel pain.
But what if the fetus is removed from the womb and its sleep-inducing chemicals? Will the fetus suddenly be conscious in the outside world? In adult humans, for normal consciousness to occur, it is now generally agreed that two sets of regions need to be intact, functional, and able to communicate effectively with one another: the thalamus, a kind of relay station in the middle of the brain that connects many regions with many others; and the prefrontal parietal network, our most high-level, general purpose section of cortex. If either the thalamus or prefrontal parietal network is substantially damaged, the patient is likely to enter into a vegetative state, with virtually no sign of consciousness.
When do these brain regions form in the growing fetus? Only after about 29 weeks are the connections between these areas properly laid out, and it takes another month or so before the thalamus and the rest of the cortex are effectively communicating, as revealed by brain waves. So it’s highly unlikely that consciousness, at least in any form that we’d recognize as human awareness, arises before about 33 weeks into pregnancy. There are therefore no scientific reasons for restricting abortion on the grounds that the fetus will experience pain, at least until very late in pregnancy. This evidence has heavily influenced my views here, and consequently I am very much pro-choice.