According to Luc Bovens, professor of philosophy at LSE, the rhythm method is the moral equivalent of the contraceptive pill. In other words, the one method of contraception recommended by the Vatican is, by their own standards, murder.
On Dissection, the science blog at SMH.com.au, Julie Robotham writes:
Part of Catholics’ opposition to the contraceptive pill, he points out, is that it in the event that a woman ovulates despite it and the egg is fertilised, then the pill’s effect on the lining of the uterus may prevent the resulting embrryo from implanting. Since, according to Church doctrine, life begins at fertilisation then that can technically be interpreted as an abortion. Ditto for the intrauterine device (IUD).
In natural menstrual cycles, free from hormonal or pharmaceutical or mechanical manipulation, there is an optimal time of conception – within a day or two of the egg being released from the ovary. Leave them too long and they start to pass their prime, less able to carry the genetic recipe for a healthy baby.
So, Bovens says in the Journal of Medical Ethics, it’s reasonable to assume that some of the rhythm method’s effectiveness comes not from preventing the egg and sperm getting together in the first place, but from the creation of runt embryos that don’t stand a chance of passing muster in the great Darwinian survival race. Add a decaying uterus lining later in the cycle and the poor clump of cells doesn’t stand a snowball’s.
Read the rest of Robotham’s post here.