We are the same as HK - the simplest honest explanation possible offering only as much information as the child pursues, which often turns out to be not much.

And we also tailor the response to the cause of the question, we've not had to deal with abortion directly, but we have had to explain late pregnancy loss, adult death, and various other big life issues.

Surely a children's almanac will have fairly matter of fact and extremely unsexy explanations of reproduction? I would see that as a good thing? A book often recommended to us is "Everyone's got a bottom".

Good luck!