The answer to this problem is simple. Create a situation where women see it as an advantage to have children younger, and in wedlock too.
This is of course beyond the wit of the liberal establishment.
They of course prefer to wring their hands at the increase of single mummery, family breakdown, rising crime, ever-lowering standards of education and behaviour, make us pay paedophile and green taxes and rejecting any solution that might work because it might seem judgemental, intolerant and insufficiently compassionate.
Perhaps it is time they were sent on their way after so many decades in power.