Wednesday, July 2, 2014

Contraception, Implantation and "Evidence-Based Medicine"

One of the "interesting" aspects of the Hobby Lobby case is that it is based on the false assertion that the birth control methods in question are "abortifacient."  Apparently this is a widely held belief.  I keep reading comments to the effect that, "Hobby Lobby shouldn't have to pay for abortions," or "Hobby Lobby is fine with covering regular birth control pills, just not the abortifacient ones."  Surprisingly, SCOTUS did not even address the scientific evidence underlying this assumption, but rather, chose to accept Hobby Lobby's "belief" as being sufficient.  But, what does science tell us about the situation?

First of all, the fundies have changed the definition of pregnancy and abortion to include "preventing implantation" as a method of "abortion," which it is not.  According to the standard mainstream medical definition per the AMA and ACOG, pregnancy occurs when a fertilized ovum successfully implants in the uterine lining, an event which happens only about 40% of the time under optimal conditions, about a week after fertilization.  So, contrary to popular belief, even in the absence of contraceptives, most fertilized ova do not result in an established pregnancy and are expelled with the next menses.  The "pro-life" movement, however, insists on equating "pregnancy" with fertilization.  Part of the reason for the confusion is that the word "conception" has been used to refer to both fertilization and pregnancy, allowing the definitions to become blurred in the minds of laypeople.

Secondly, regardless of the definition of pregnancy, and more important to this argument, birth control pills, whether traditional daily pills or "emergency," do not prevent implantation!  I have been unable to find any scientific studies documenting this alleged mode of action of oral contraceptives changing the uterine lining to make it "hostile" to a fertilized ovum.  The NIH specifically states that the mechanism of action of these hormonal agents is to prevent ovulation.  If there was any doubt about this, what finally convinced me was an article published by the American Association of Pro-Life Obstetricians & Gynecologists in which they looked at all the available data and concluded that there was absolutely no evidence for it.  This article was extremely thorough and examined the effects of hormonal contraceptives on the menstrual cycle in some depth and in great detail.  These pro-life doctors state in conclusion:  "It is not the purpose of this paper to promote nor to oppose hormone contraception. However, if a family, weighing all the factors affecting their own circumstances, decides to use this modality, we are confident that they are not using an abortifacient."

So it should be a moot point. Where is everybody getting this crazy idea?  From the FDA labeling, which states on all birth control pills (not just Plan B and other "emergency" pills) "may prevent implantation" although there is no scientific evidence whatsoever to substantiate this claim! Everybody has accepted the notion as fact when it is not. So, why is it on the label? Can't we trust the FDA to adhere to "evidence based medicine"?! 

Maybe not.  The FDA does not conduct its own research; rather, it relies on studies conducted and/or funded by the drug companies themselves, which tend to provide results favorable to the desired outcome.  In addition, many of its members have financial ties to the pharmaceutical industry which may influence their objectivity. 

My theory is that the label reflects "wishful advertising" in that it was originally hoped by the manufacturers that oral contraceptives might, in fact, work in that manner.  It would have made them more effective and a great selling point!  Back when the FDA approved the original labeling there were no concerns about "abortion" in terms of fertilized ova; that idea is a more recent fabrication by the anti-abortion movement. 
 The manufacturers of the drugs would need to request that the labeling be changed, which apparently is a tedious and expensive process.  Perhaps they will do so now that prevention of implantation is no longer seen as a desirable feature of the drugs due to the anti-abortion movement's influence in swaying public opinion.

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