A link from this mailing list I’m sort of on, in one of the few threads I’ve been reading: a scientist criticises the rhythm method as a killer of embryos. Essentially, he’s saying that the incidence of intercourse at the fringes of the fertile period causes conception of far more embryos that can’t survive, and therefore that many more embryos are conceived and then die by this very calculated means than by other forms of contraception. Interestingly, he reports that Roman Catholics have statistically higher rates of miscarriage, at least according to one study — but of course, this is …