Mississippi’s “personhood” amendment – up for a vote on November 8th – would certainly be damaging to women’s reproductive health and rights. But the media has consistently reported its implications incorrectly. Even if passed, emergency contraception using levonorgestrel (Plan B) and IUDs should still be accessible.
According to the New York Times, the amendment, if passed, “would declare a fertilized human egg to be a legal person.” The Times goes on to report that abortion, in-vitro fertilization, and even IUDs and emergency contraception might become unavailable as a result. The Guardian relays the same message.
But here’s the thing. IUDs and emergency contraception do not do anything to fertilized eggs. All the most recent science shows this. Both contraceptive methods prevent fertilization (the mainstream media has continued to repeat this flawed interpretation). In fact, just this week yet another study showing that Plan B works by preventing ovulation was published. The study measured women’s hormone levels to determine where they were in their menstrual cycle at the time of unprotected sex. They identified 103 women who had sex in the 5 days prior to ovulation, and 45 who had sex in the 5 days after ovulation. Among the 103 who had sex prior to ovulation and took plan B, none got pregnant, though statistically if Plan B doesn’t work 16 should have gotten pregnant. Meanwhile in the other group 8 got pregnant, while statistically 8.7 should have gotten pregnant. In other words, Plan B only works if you haven’t ovulated yet. If you’ve ovulated, the hormones don’t do anything to prevent sperm and egg from joining and implanting in the uterus. It has no effect on fertilized eggs.
The IUD is a bit more complicated because it works in multiple ways, and there are 2 different kinds of IUDs. However, the preponderance of evidence shows that the IUD also does not do anything to fertilized eggs. Rather, it prevents fertilization. The copper IUD alters the cervical mucus, making it nearly impossible for sperm to enter the uterus to meet an egg. If sperm do enter, their motility and ability to fertilize an egg are reduced due to the inflammatory reaction induced by the IUD. Those few studies that have looks at intra-uterine sperm after IUD placement have found that there are many fewer sperm and that they aren’t able to move like those sperm found in the uterus of a woman without an IUD. The copper IUD works by keeping sperm from getting to and fertilizing the egg; no evidence suggests it has any effect on fertilized eggs. The levonorgestrel IUD (Mirena) is less well-studied than the copper IUD, but evidence suggests it also impacts the cervical mucus, decreasing the number of sperm that enter the uterus, and decreases the chance of ovulation by releasing levonorgestrel into the bloodstream. In other words, it prevents fertilization. No fertilization means no blastocyst, which means no embryo, which certainly means this amendment has no bearing on IUDs.
Yes, there are some unanswered questions. What happens if you insert an IUD between the time an egg has been fertilized and it has implanted, or if it has just implanted? Nobody knows, and nobody ever will know, because it’s just too hard to study. It’s possible that there are some little embryos out there that get dislodged without anyone ever knowing it during IUD insertions. We also don’t know nearly as much about the new emergency contraception pill, Ella (ullipristal), as we do about Plan B, and it’s possible it works by preventing implantation of a fertilized embryo. Probably because of these uncertainties, and because it was approved by the FDA years ago before we had this recent research, packaging for products like the IUD and emergency contraception often perpetuates misconceptions about their mechanism of action. But all the recent science points away from any effects on fertilized eggs, and frankly, I’m not losing a lot of sleep about those rare situations where a fertilized egg might be affected. Every medical procedure or drug has the possibility of a negative impact. If I were to lose sleep about things like this, I’d never be able to practice medicine. I’d always be worrying if the person I recommended a cholesterol-lowering drug to was one of the rare people who would develop liver failure as a result, or if the person I recommended to start biking to work for more exercise would be one of the few people to get hit by a car. I’m certainly not going to worry about the theoretical possibility of disrupting a fertilized egg.
In medicine, we can’t allow speculation and worry about what might be to overshadow the facts. The facts are that, based on the most recent science, IUDs and emergency contraception do nothing to fertilized eggs, much less embryos or fetuses, and the mainstream media needs to stop repeating tired, disproven theories in reporting on this amendment.