Almost nobody in the UK is the extreme kind of "pro-life" that wishes to prohibit abortions where pregnancy will kill the mother, or where the foetus will be born only to die in agony a few hours/days later, or where the foetus is just a body with no brain, etc.
And almost nobody in the UK is the extreme kind of pro-choice that wishes to allow abortion of foetuses right up to term for any or no reason (and if they do argue for this, it's generally with the understanding that in reality, women would almost never actually choose to abort a late-term pregnancy for no good reason).
So it's difficult to make blanket statements about ethical soundness of different positions as if it's an easy comparison, when neither of the positions debating is taking a clear-cut, clean, absolutist stance.
There are always muddly bits discussing degree of risk and suffering for the mother, degree of potential suffering in the foetus, and so on. Abortion in the UK isn't on-demand, it's about risk of damage and suffering, including mental.
So, assuming you're not the kind of extremist who's happy to see women like Savita Halappanavar die, how is your position "ethically much more sound" if what you're doing is just taking a slightly different view on, for example, what level of suffering and risk is okay to require people to accept?