Yes, there's the career women stuff bandied around, women being blamed for the rise in in numbers giving birth over 40.
However, amongst my peers many of us would have happily taken time off from careers earlier if only we'd been able to settle down with a suitable partner earlier.
It makes my teeth itch that women are being blamed for this rise when lots of women would love to have settled down with a suitable man and started a family 5 or 10 years earlier than they actually did but many men these days are not ready for that commitment and end relationships with women who are ready, causing them both to start the search for a suitable partner all over again.
Part of the cause in my opinion (and experience) is the rise in the numbers of the "man-child" who wants to have relationships with women but not to settle down to starting a family (as that is when hard work comes into the relationship) and it becomes less fun-based.
Men are far more responsible for the rise in numbers of women giving birth in their 40's, than women are.