Seems to me that v-e, among others, is conflating several issues. Late-term abortions, after all, happen (by definition) rather late for them to be treated as some form of contraception; would that not more likely apply to earlier abortions? Pregnancy itself can be inconvenient -- or so I'm told, how could I know really? -- so it would be a strange person who decided to endure 30-odd weeks of pregnancy and only *then* thought it was inconvenient.
"Inconvenience" is, perhaps, a harsh word and I can't speak for mothers who view it that way. But perhaps it's shorthand for "I simply do not have the emotional strength, wherewithal, desire, etc., to bring a child into the world and then raise them for years and years to come". In such circumstances, whatever the reasons -- and I fancy that even my longer version still barely scratches the surface of something that, if you aren't planning for it, must be *scary* -- is it not the lesser evil to terminate what was only a potential life, rather than to bring a child, unwanted, into the world?