A life begins... OR WILL IT????
It's not just the Catholics who have voiced this condemnation of the "abortifacient" properties of birth control. The Evangelicals who fill the ranks of the pro-choice movement are similarly quick to criticize any use of "unnatural" hormonal contraceptives. There is the outstanding example of the Duggar family, who believe that their use of the Pill caused the miscarriage of one of their pregnancies back in the '80s, and have spent the past two decades atoning for this crime by pushing the limits of human reproductive capacity. Just a quick Google search will yield a bevy of emotionally-charged, poorly-researched, and often blatantly deceptive websites devoted to defaming all birth control use and equating contraceptives with murder. (Notable examples including Birth Control is a Sin, Birth Control Causes Abortions, AbortionFacts.com, and perhaps most horrifying, PoisonedByThePill). A common thread throughout these websites is that of deliberate deception at the hands of doctors and pharmacists. Readers are urged to "read the fine print" and "wake up" - as if the entire medical profession were aligned in some giant conspiracy to kill Evangelical embryos for the good of Science and Atheism and Richard Dawkins.
From this movement has grown a plethora of misconceptions and taboos about the "Morning After Pill" and oral contraceptives. Many women worldwide are misinformed about emergency contraception and its mechanism of action: some actually mistake the Plan B pill with RU486, the "abortion pill." Pro-life lobbying on this issue has also spawned “the Pharmacist’s Conscience Clause,” a provision which allows a pharmacist to withhold oral contraceptives and the "morning after pill” on moral grounds. A recent study estimated that 6% of American pharmacists actually withhold contraception - which probably makes it pretty difficult to purchase birth control in Kansas. This poor understanding of emergency contraception deters many genuinely well-meaning women and couples from choosing Plan B following unprotected intercourse - which, of course, is the intended effect of the religious fear-mongering.
Now, Pope Paul VI was not a doctor or a biologist, so I was interested in how he arrived at his understanding of the mechanism of action of birth control pills and emergency contraception. So I popped on over to PubMed to see what relevant (and unbiased) information medical researchers had discovered on the topic.
But first, a little background on early embryonic development: the human embryo typically implants in the uterine wall at the blastocyst stage, approximately one week after fertilization, when it consists of 32 cells. To prevent a subsequent pregnancy, the ovaries begin secreting progesterone, a hormone which inhibits further ovulation. Progesterone also inhibits the process of sperm capacitation, which enables a sperm to fertilize an egg. In addition, this hormone thins the lining of the endometrium - just like it does during the luteal phase, i.e. a menstrual period.
Both oral contraceptives and older versions of the Plan B pill (which is essentially a higher dose of the same thing) rely on progestrin, a synthetic form of progesterone, essentially to trick the body into believing that it is already pregnant. Thus, ovulation and sperm capacitation do not occur, and the endometrial lining thins. It is this capacity of progesterone which has conservatives jumping down throats and splitting hairs about what constitutes prevention vs. termination of pregnancy, and losing sleep over the fate of the human blastocyst.
So let's see what a few decades of medical research have to say on the matter. First, newer Levonorgestrel-based contraceptives (such as Plan B One-Step) can apparently only prevent ovulation, and cannot prevent pregnancy once ovulation has occurred. No studies indicate that Levonorgestrel has any "abortifacient" capabilities. Thus, Levonorgestrel is only 80% effective at preventing pregnancy. The results of studies on progesterone-based pills are a little bit hazier: some report "with mild confidence" that progesterone prevents implantation, while others deny this to be the case. Most review articles state that the prevention of implantation is "possible in theory," but do not provide relevant statistics. In contrast, the post-coital insertion of an IUD has been shown to prevent implantation of an embryo; Mifepristone, the "abortion pill," can be taken in small doses to produce the same effect.
The general medical consensus: certain forms of emergency contraception (Mifepristone and IUDs) have the secondary effect of preventing embryonic implantation. However, the most commonly-used form of emergency contraception (Levonorgestrel), does not act in this way. In regards to the Pill, it is possible in theory that these contraceptives prevent the implantation of a fertilized embryo, but no study to date has strongly indicated that this is the case. I speculate that the findings of such studies are complicated by the fact that, even in the absence of birth control, at least half of fertilized human ova do not successfully implant. Here's a little graph I threw together about the prevalence possible fetal fates in the U.S.:
Needless to say, these stats are going to make Georgia Rep. Bobby Franklin's job very difficult if he in fact intends to investigate and press charges for every miscarriage that occurs in his state. The majority of fertilized oocytes to not make it to be full-fledged humans, even without medical or chemical interventions. Ultimately, it is difficult to determine how often emergency contraception prevents an embryo from implanting when God Himself is already doing such a good job of it.
Needless to say, these stats are going to make Georgia Rep. Bobby Franklin's job very difficult if he in fact intends to investigate and press charges for every miscarriage that occurs in his state. The majority of fertilized oocytes to not make it to be full-fledged humans, even without medical or chemical interventions. Ultimately, it is difficult to determine how often emergency contraception prevents an embryo from implanting when God Himself is already doing such a good job of it.
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