I have a huge mental blank and am trying to remember a book I read a few years ago (probably about 6 or 7 years ago). It was British, written by someone like Ian McEwan but not (I think) Ian McEwan. All I remember is that one of the themes/subthemes was a long term affair between a married man and a younger woman (who had some kind of high powered career) and she becomes pregnant to him. Towards the end of the book she goes into labour at her home, while the married man is driving towards her. The married man ends up delivering their baby in her garden. Ring any bells??