Is the Rhythm Method - "the only method of birth control condoned by the Catholic Church" - responsible for "massive embryonic death"?

There is an article forthcoming in the June issue of the Journal of Medical Ethics, by professor Luc Bovens, a professor of philosophy at the London School of Economics entitled, "The rhythm method and embryonic death" (J Med Ethics 32: 355-356).

A story has been buzzing around the news wires prior to the article's publication that I've reproduced below:

'Rhythm method' may kill off more embryos than other methods of contraception

The "rhythm method" may kill off more embryos than other contraceptive methods, such as coils, morning after pills, and oral contraceptives, suggests an article in the Journal of Medical Ethics.

The method relies on abstinence during the most fertile period of a woman's menstrual cycle. For a woman who has regular 28 day cycles, this is around days 10 to 17 of the cycle.

It is the only method of birth control condoned by the Catholic Church, because it doesn't interfere with conception, so allowing nature to take its course.

It is believed that the method works because it prevents conception from occurring. But says Professor Bovens, it may owe much of its success to the fact that embryos conceived on the fringes of the fertile period are less viable than those conceived towards the middle.

We don't know how much lower embryo viability is outside this fertile period, contends Professor Bovens, but we can calculate that two to three embryos will have died every time the rhythm method results in a pregnancy.

Is it not just as callous to organise your sex life to make it harder for a fertilised egg to survive, using this method, as it is to use the coil or the morning after pill, he asks?
Professor Bovens cites Randy Alcorn, a US pro-life campaigner, who has equated global oral contraceptive use to chemical abortion that is responsible for tens of thousands of deaths of embryos, or unborn children, every year.

But says Professor Bovens: if all oral contraceptive users converted to the rhythm method, then they would be effectively causing the deaths of millions of embryos.
Similarly, regular condom users, whose choice of contraception is deemed to be 95% effective in preventing pregnancy, would "cause less embryonic deaths than the rhythm method," he says.

"the rhythm method may well be responsible for massive embryonic death, and the same logic that turned pro-lifers away from morning after pills, IUDs, and pill usage, should also make them nervous about the rhythm method," he contends. [source]

Now, there are MANY things in error with this article. I'll try to tackle a couple myself, but the important thing to realize is that little stories like this have a habit of taking up residence in the mind of some people as "valid problems" with the Church's teaching on sexual ethics.

Anyway:

• The "Rhythm Method" is not "the only method of birth control condoned by the Catholic Church." Statements claiming the Church only supports the rhythm method reveal more the ignorance of their authors than anything else. Natural Family Planning - not the Rhythm Method - is supported by the Church, and for good reason.
• There can be no "embryos" conceived outside the of the fertile period of a woman. This article says "The method relies on abstinence during the most fertile period of a woman's menstrual cycle." Natural Family Planning, on the other hand, relies on abstinence during the entire fertile period. Let's review: No fertility = no embryos = no "massive embryonic death." Now, what they do mean to say is that the old rhythm method, which did not take into account the fact that a woman could conceive (during her fertile period) even several days after sex (from that one act of sexual intercourse), could result in pregnancy. Essentially, Prof. Bovens makes his startling revelations based on a point that the Church has understood for sometime, and which is no longer (if ever) supported or recommended. But the article goes even further.
• "Is it not just as callous to organise your sex life to make it harder for a fertilised egg to survive, using this method, as it is to use the coil or the morning after pill, he asks?" Suddenly the article jumps into the realm of morality. Instead of sticking close to the biology, the article takes its "revelation" about the defects of the (discarded and old) rhythm method and tries to chip away at the Church's sexual teaching with it.
• "if all oral contraceptive users converted to the rhythm method, then they would be effectively causing the deaths of millions of embryos. " Good point, but the Catholic Church isn't telling people to switch to the rhythm method. Switching to NFP would result in no pregnancies (99.5% success rate). How would the professor respond to that?
• "Similarly, regular condom users, whose choice of contraception is deemed to be 95% effective in preventing pregnancy, would "cause less embryonic deaths than the rhythm method," he says." Presuming, of course, that condom users would not terminate the pregnancy. Again, this claim is off-point - the rhythm method is a moot point for Catholics.
• The final sentence: "the rhythm method may well be responsible for massive embryonic death, and the same logic that turned pro-lifers away from morning after pills, IUDs, and pill usage, should also make them nervous about the rhythm method," he contends." You're so right, professor. Sadly, you never took the time to research whether they actually have discarded the rhythm method.

I think this article is a classic "straw man" argument. The article deliberately claims "The Church teaches X (the old rhythm method, in this case)," and then proceeds to gloriously poke holes in it with the aid of trusty science. I don't think I'm reading into this article at all when I say that it is deliberately trying to discredit the logic of pro-lifers and the Catholic Church.

Happily, logic is and will always be on the side of pro-lifers and the Catholic Church, so I'm not worried.

An even more inflammatory version of the article, posted here at the Sydney Morning Herald, is provoking a sharp response in the comments section.

The Dialogue blog explains a bit how Natural Family Planning works in response to this article.

Hat tip to Shelray of Cosmos-Liturgy-Sex for originally spotting the article.