Aubergine - I agree, working patterns, the way we build cities, the fact that suburban schools are seen as better and less challenging environments than inner city ones - all of this matters for why women disproportionately give up their career aspirations on becoming parents, even if they eventually go back to some kind of work which fits around motherhood.
I agree the answer is not longer childcare - the answer may not be to do with childcare at all.
I think the answer has to challenge the deeply engrained idea that becoming a mother is fundamentally different than becoming a father, that women only have "starter" careers which they can put down for spells of 5 years or more, that part time work is out of the question for the primary earner, that women's careers matter less and that women should be expected to be the primary parent.
If men faced a situation where having a couple of children meant giving up work for 5 years and then only being able to go back to local/no pressure/regular hours/no travel positions (for which they will be competing with 100s of other dads willing to accept low pay in return for family-friendliness) ...and that that is ok because they would get subsidised childcare (to make up for the fact that they had so stunted their careers that it is hardly worthwhile to work at all...) - I don't think many would have children in the first place.
(by the way, I think the subsidised childcare and family tax breaks etc... offered in many European countries were designed as measures to counter falling birth rates, not inequality at work)
It doesn't sound like the model of subsidised childcare in Bavaria, Berlin and Belgium has done the trick to make expectations of mothers and fathers equal .