Anecdotally, my female Japanese friend outright rejected the idea of going back to work after having a kid and said that lots of her friends feel the same way. There seems to be a strong cultural thing around women becoming stay-at-home mom's instead of rejoining the workforce.
I'm not going to comment on 'pressure', but I've noticed that companies with formal vacation policies seem to be better for women on mat leave because they can stack their accrued time on top of the mat leave policy.
Maternity leave refers to a specific employment benefit. We’re you genuinely confused or trying to make some other point? In the latter case, is it relevant to this thread?