Education is the ultimate key to improving outcomes, though.
So educate parents through Sure Start centres, make it as easy as possible for children to stay in school and get an education - this involves looking at what schools are actually for, as the current curriculum may not be fit for purpose.
I’d also make child maintenance a factor in any benefits received, and child maintenance to be calculated as 50% of a notional cost per child not depending on income. This would not reduce the amount the resident parent receives from the State, but the non-resident parent would have to reimburse the State for benefits paid that they - as the other parent - should have been responsible for. The debt could be interest bearing and repaid in the same way as student loans, but not written off.