I'm not sure how science backs you up, as babies have been known to survive when born earlier than that, very rare of course, but it happens. Also there's a heartbeat long before 24 weeks and the foetus starts to move before then as well.
The law backs you up in this country, but the legal limit is earlier in other European countries. So it's pretty arbitrary and doesn't prove much.
I hardly think the world over it's true that more men are forced to be fathers against their will. In India and China everything favours the men. And in Africa as well. Even if they become fathers against their will, they don't have to do anything about it, the woman is left holding the baby.
In the Western world you do have a point, as women do have more rights and have autonomy over their bodies. But men do still walk away regularly with impunity.
I'm not saying you shouldn't disagree, that's your right. But rudeness isn't on, it actually weakens your argument.
In any case, our personal opinions are not really the point here. There are a lot of women on Mumsnet who are firmly pro choice but wouldn't have one themselves. What you're arguing is that they should go against their instincts and terminate their pregnancy if their partner doesn't want a child in the case of a genuine contraception failure. Because that's the only way a man could opt out of parenthood.
I'm very sure some women do just that. Because they have to choose between having a baby and their relationship and obviously sometimes they don't want their relationship to end.
But no one on Mumsnet would advise her to terminate her pregnancy just because her partner didn't want a baby. The advice would be to do what's right for her. It's an agonising decision for a lot of women.
I don't see that there's a solution to this so in essence we're just going round in circles.