The most recent scientific study on Levonorgestrel, the essential component of the “morning-after pill” or “emergency contraceptive,” confirms that the drug does indeed have a third effect on users, which consists in preventing the implantation of a fertilized ovum in the womb of the mother.Here is another post from prolifeblogs that mirrors this thought:
A study published in the journal Fertility and Sterility found that levonorgestrel, the drug contained in Plan B emergency contraception, does inhibit implantation after all, at least some of the time. (Preventing implantation interrupts an existing pregnancy and is an abortive mechanism.)Interesting stuff, until you realize that both claims are completely untrue. Here is the abstract of the study in question. The investigators used computer models to determine the effectiveness of LNG as contraception if it acted via a pre-fertilization mechanism and compared it to the effectiveness if it also had a post-fertilization mechanism. The results were this:
With disruption of ovulation alone, the potential effectiveness of levonorgestrel EC ranged from 49% (no delay) to 8% (72-hour delay). With complete inhibition of fertilization before the day of ovulation, the potential effectiveness of levonorgestrel EC ranged from 90% (no delay) to 16% (72-hour delay).This is not surprising at all, although it may very well be helpful if real experimental data ever come out that confirms the actual effectiveness of LNG. In fact, this post of mine essentially predicts these numbers. In the meantime, the authors do note that the projected effectiveness of LNG if it acts via a pre-fertilization mechanism is lower than the effectiveness rates reported in the literature. However, it is precisely those rates that have been previously reported that are under question not only by me, but by a number of pro-EC researchers. This study does nothing to shed light on the true effectiveness of LNG EC, and thus cannot confirm its actual mechanism at all. The authors understand this when they conclude:
The gap between effectiveness of levonorgestrel EC estimated from clinical studies and what can be attributed to disruption of ovulation may be explained by overestimation of actual effectiveness and supplementary mechanisms of action, including postfertilization effects.Reporting that this paper confirms a post-fertilization mechanism for Plan B is completely irresponsible. Reporting the results of scientific papers using your ideology to cloud what they actually say is simply wrong.