New Scientist has an article "Rhythm method criticised as a killer of embryos":
“If you’re concerned about embryonic death,” Bovens says, “you’ve got to be consistent here and give up the rhythm method.”
For the record, I came up with my analysis independently. I quoted some research that actually shows this happens. I pointed out that this related directly to the argument about "Plan B." Funky Dung, of Ales Rarus, correctly suggested that this will require a modification to NFP.
You saw it here first! I wonder if anyone will footnote this blog.
I’m not sure if this proves anything. People have often pointed out that many embryos die in utero, often to imply that they aren’t truly human as a result (which makes perfect sense if you ignore the 100% mortality rate of all humans).
Natural Family Planning, which is not the rhythmn method, does not *do* anything to intrinsically harm or endanger the embryo, such as by endometrial thinning in the case of some or all chemical contraceptives or abortifacients. If NFP did that, yes, we’d have to take stock of it. But this could happen to a couple not using any sort of precaution or regulatory method. It’s just nature, rather like arthritis, pneumonia, and brain cancer.
This is merely a revival of what we know the in-utero mortality rate, and more mud thrown in an already rather unproductive national debate.
Jerry,
You’ve missed the point. NFP alters when intercourse will take place, dramatically increasing the chance of embryo death. This can be directly related to the technique.
Given that “Plan B” is unacceptable because there is a statistically undetected and biochemically improbable chance that the drug might prevent implantation, then NFP is far, far worse. There would be fewer abortions if contraceptives were used with abortion for the minute failure rate.
I haven’t even gotten into the huge list of things accepted by the Catholic church that are known to sometimes cause spontaneous abortions at a far higher rate than “Plan B.” No one seems to be attempting to ban them and pharmacists don’t object to distributing them.
The point I am attempting to make, as did someone in the New Scientist article, is that the true opposition to “Plan B” is that it is contraception, not because it is an abortificient. The public may sympathize with pharmacists who refuse to fill prescriptions for abortificients; my guess is there would be far less sympathy for pharmacists who refuse to fill prescriptions for contraceptives as a matter of conscience.
Misinformation and deliberate contradictions in policy are being promoted, not for religious or scientific reasons, but for tactical political reasons. People are deliberately and knowingly lying to advance their cause. I object to that — on any side.
I’m funny that way.
Thank you for the clarification. I’ll look into this further.
There’s still a distinct difference between an abortifacient drug (which Plan B may or may not be) and ill-timed intercourse. The latter only results in the death of “unfit” embryos, while the former also kills viable embryos.
Dear Rob,
I’m not sure if you’re aware of this, but it seems to me the two sources you cite actually contradict each other.
The first source finds that the rate of miscarriage is about the same for both conception during the fertile period, and on the fringes of the fertile period (around 10%). The only circumstance in which this didn’t hold true was if the female had a history of miscarriages (then it’s 23%).
The second source suggests a 50% rate of miscarriage for conceptions on the fringes of the fertile period, and fails to place this in any context of miscarriages from fertile period conceptions.
It should also be noted that the first is a medical study, whereas the second is the reasoning of a philosopher whose conclusions are based on assumptions which I don’t see supported (one of the primary ones being the 50% rate mentioned above). That’s why most of the article uses the language of “may”, “plausible”, and “if”, as opposed to the first which uses terms like “there were” and “we observed”.
Further, I think it’s pretty obvious that the natural expulsion of a fertilized egg resulting from aged gametes is different than altering a woman’s reproductive systems to prevent/reject a fertilized egg.
BV:
The 50% in the second article refers to the 40-60% failure to implant successfully for all fertilized eggs. There are several genetic “tests” of the fertilized egg. If there are too many or insufficient chromosomes, if methylation did not occur correctly on a maternal or paternal chromosome, or if there are broken chromosomes or the chromosomes do not segregate in the first meiotic division or if the mitochondria are grossly defective, the egg cannot implant. Even if it can implant, it may not be capable of sending the proper signal to the mother, resulting in the lining and egg being lost. If the placenta cannot develop properly, the embryo will starve. Biochemical signals are exhanged between the embryo and the mother — if the wrong signals are sent or not received, the cells will be destroyed.
All those “missed periods” where the period starts up again and the woman decides she wasn’t pregnant after all? Most of them are probably pregnancies that failed.
The failure rate to implant and last long enough to be detectable as a pregnancy is 40-60%, depending on who you listen to. The overall failure rate is generally agreed upon to be about 80% — only 20% of conceptions reach full term. The 19% rate at certain clinics for non-PGD non-fertilization assist (where the sperm is actually driven into the egg with a needle) is not statistically different from normal rates. If one is not opposed to IVF a priori, the best clinics can offer essentially normal implantation rates, eliminating the argument that IVF is a form of abortion.
If you’re wondering how a 40-60% range can result in 80% with no range, there’s a question about multiple fertilizations — and this happens without fertility drugs. One embryo can merge with another, “eat” another, or kill it — or they can kill each other, a situation that arose with the twins of an actor who plays on Law and Order. The twins were killing each other and they decided to kill one of the babies so that the other could live. How would you like to have to face that choice?
There’s actually a lot more going on in this topic, and a lot of debates and questions, but I’ve simplified the basics for you.
I think I left out a lot about some weird genetics that might be going on. It’s really cool, if frightening.
Dear Rob,
Thank you for the background. If I’m understanding you correctly, the 50% rate refers to the percentage of fertilizations that fail to become pregnancies, while the 10% rate refers to the percentage of pregnancies that result in miscarriages?
Reading the second article again, the philosopher’s reasoning seems to be incomplete. Here’s his crux, as far as I can tell:
“Bovens calculates that, if the rhythm method is 90% effective, and if conceptions outside the fertile period are about twice as likely to fail as to survive, then ‘millions of rhythm method cycles per year globally depend for their success on massive embryonic death’.”
Breaking this down:
1) IF the rhythm method avoids pregnancy 90% of the time, AND
2) IF conceptions outside the fertile period fail 66% of the time,
3) THEN the rhythm method results in millions of embryonic deaths
There seems to be step missing here: what portion of the “90% effective” are due to conceptions that fail? Yes, it is possible that some of this effectiveness is due to aged gametes which fail to implant. But I think it’s quite a leap to say all of the effectiveness is from this phenomenon (i.e. what about conceptions which never occur in the first place?). And without this link, I can’t see how you can extrapolate the number of embroynic deaths resulting from the rhythm method.
In speaking of the 90%, the person is doing a “back of the envelope estimation.” He’s assuming a “God’s view” of the effectiveness of NFP.
The exact numbers do not matter to me, except to say that the number of fetal deaths caused by people using NFP will be far in excess of anything that could possibly be for “Plan B.”
See, with NFP, there are several plausible mechanisms by which embryonic deaths would occur that would not occur normally. There is data to back this up, at least in the case of women with known problems with pregnancy.
There is no known mechanism by which “Plan B” would cause embyros to fail to implant. That was a guestimate from the time when chemical birth control was first developed. Statistically, it cannot be demonstrated from any research done so far. The most that can be said is that it cannot be proven to never, in the entire history of the universe, occur.
I don’t think bagels would meet that criteria — certainly not onion bagels.
A different take on the Bovens proposition:
http://epiph.blogspot.com/2006/05/hypocrisy-at-its-worst.html
[…] St. Blog’s Parish will soon be all aflutter with news that a British professor of philosophy, Luc Bovens, has written an article ("The rhythm method and embryonic death", J Med Ethics 32: 355-356) that links the use of the "rhythm method" with embryonic death, i.e. early miscarriage or spontaneous abortion. (Fedora Tip: UnSpace) […]
For those interested in reading the full article and abstract:
http://jme.bmjjournals.com/cgi/content/full/32/6/355
And official responses sent to the Journal of Medical:
http://jme.bmjjournals.com/cgi/eletters/32/6/355