The best person to explain an artist’s inspiration and motivation is the artist themself, and in a 2012 interview with Adelaide Damoah, which you can read in full here, Ruth Bircham gave some perceptive and personal responses:

As adults, most of us will have sex at some point in our lives, so it shouldn’t be something which is hidden. It is a beautiful thing. In certain parts of Africa they will not touch the subject. I am still trying to get an exhibition of this work to happen in Nigeria, and have been turned down by twenty galleries so far! I once exhibited at a gallery in Nigeria where the owner was shocked by my work. There were fragments of breasts, legs and vaginas all over, and she didn’t like it at all. I was demonstrating the male gaze, in which men often do not look at a woman as a whole. They see her in fragments, saying things like ‘she has nice breasts’ or ‘I like her bottom’. When I explained it to her in these terms she was a bit more understanding.
     I had my first solo show in 2009. One woman approached a painting and said, ‘Is that, erm …’. She couldn’t bring herself to say what it was. It was a penis. People are afraid to say penis, and people are afraid to say breast. After that, I decided that my next exhibition would be even more explicit! I was involved in a group show in November 2011 called ‘Hidden Fruit’. My work was the most explicit work in the show. I hung it on the wall opposite the entrance so it wasn’t hidden. We all need to accept who we all are as human beings.
     My dream is to get a new erotic art movement off the ground. I want artists to realise that being bold, being expressive and loud in your work. is the best way forward. We shouldn’t allow other people to restrict us or tell us what to paint. My aim is to motivate artists to create art in the way that they want to create it. I am very determined!