What it says on the tin really.
My husband and I are finally earning enough to enable us to donate to a couple of charities each month. We have been discussing causes which are important to us and although we haven't fully decided yet, we think we want to focus on charities which help sick children. GOSH being one of them. Maybe Ronald McDonald or the children's hospices such as Rachel House (we had close friends who used it and can't speak highly enough of it). Perhaps something like the children's hospital at the new big hospital in Glasgow.
I guess the reason is that we have two young children ourselves and we are lucky enough that they are healthy. Some of our friends haven't been so fortunate.