As a physician, I can explain how the device works.
The general conclusion from review of this literature from both the American College of Obstetrics & Gynecology as well as the American Academy of Family Physicians is that IUDs work by:
1) Preventing the entrance of sperm into the uterus
2) Preventing the survival and function of sperm if they do reach the uterus
3) Preventing the ability of sperm to fertilize an egg should they make it that far
ACOG concludes in its guidelines for member physicians about IUDs: “As such, the IUD is not an abortifacient."
And the World Health Organization (WHO) states: “It is unlikely that the contraceptive efficacy of IUDs results, mainly or exclusively, from their capacity to interfere with implantation; it is more probable that they exert their anti-fertility effects beyond the uterus and interfere with steps in the reproductive process that take place before the ova reach the uterine cavity."
That being said, we as physicians never say never. So is it physiologically possible that an IUD would prevent the implantation of a fertilized egg? Absolutely. Is it likely? Absolutely not. It is probably less likely that a woman with an IUD would prevent the implantation of a fertilized egg than it is that a pregnant woman would die from her pregnancy. We do not consider it necessary or reasonable to inform patients of extremely rare and improbably risks, so the prevention of fertilization would fall into that category in regards to the IUD.
However, in medicine, we deal with people and their various subcultures and religious backgrounds and understandings. Given the very sensitive nature of the idea of “abortion” and the varied ways people define it, and the fact that there is a substantial portion of the country that believe that even a rare, remote chance of preventing implantation of a fertilized egg would be categorized as an abortion and murder, all of our educational handouts include that as a possible mechanism of action of the IUD.
Stay tuned for religious rulings on the IUD. I am in the process of collecting a few opinions from major fiqh councils and local faqih’s.
And God knows best.
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