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How exactly does IUD work?


I'm currently on a combination pill and really hate it because I can't stand the thought of synthetic hormones running through my body. I'm in a stable, monogomous relationship, never had a child, and I really don't want kids within the next three years. I've been researching alternatives and am interested in the copper IUD since it has no hormones but I'm not exactly sure how this prevents pregnancy.

I checked the tags and didn't find a specific answer to this so I'm hoping someone can help.

I read that the copper creates an uninhabitable atmosphere for sperm and, in the event this occurs, prevents a fertilized egg from implanting in the wall of the uterus, correct? My mother thinks the IUD is basically abortion birth control. I know I need to make this decision on my own but I'm not quite sure when conception actually occurs--at fertilization of the egg or at implantation in the uterine wall?

I'm just trying to do as much research as possible before I speak to my doctor and want to be clear on everything.

Thanks! :-)


( 21 comments — Leave a comment )
Aug. 30th, 2011 06:13 pm (UTC)
Pregnancy is defined in the medical community as implantation within the uterus. This is because when implantation occurs, women's hormones start changing at levels that doctors can measure. Fertilization isn't something doctors can test for reliably, so pregnancy is defined at the start of implantation.

Furthermore, abortion is defined as the termination of a pregnancy. This means that what is medically considered an abortion is something that occurs after implantation.

Interestingly, not a lot is known about just exactly how copper IUDs are effective against pregnancy. It is known that copper does inhibit sperm and that the copper IUD will make the uterus an inhospitable environment for a fertilized egg (preventing implantation), which is why copper IUDs can be used as emergency contraception after unprotected sex is had.

Now, depending on when you think life begins will affect how you feel about the copper IUD. If you believe that life begins at fertilization, this means of birth control is probably not for you. However, the copper IUD will not end a pregnancy (implanted embryo). It's potentially harmful to a pregnancy, but in itself is not an abortifacient.

This is my understanding of the medical terms of "pregnancy" and "abortion." The idea of conception and when life begins, I think, are more moral and religious issues that you need to consider before getting an IUD.
Aug. 30th, 2011 06:27 pm (UTC)
Thank you :-)
Aug. 30th, 2011 10:09 pm (UTC)
This is an excellent, nonbiased comment. A+, ditto, MTE, etc.
Aug. 31st, 2011 02:17 pm (UTC)
Amen. Great job, starzki! Beautiful summary.
(Deleted comment)
Aug. 30th, 2011 06:28 pm (UTC)
The recent study is interesting. Thank you. :-)
(Deleted comment)
Aug. 30th, 2011 08:48 pm (UTC)
My mother also told me that the IUD works by inducing abortion, which is something that I personally resent since it largely affected the way I view this method of bc. I felt like crap on pill for years, in part b/c I never considered an IUD.

If you are nervous about "passing" a fertilized egg through your body without it implanting, there was a study posted here recently which showed that the number of fertilized eggs "passed" by women with an IUD was actually lower than the number of fertilized eggs "passed" by women without an IUD (these women I assume were not on bc such as the combined pill which prevents ovulation). In other words, the body often naturally passes fertilized eggs without implanting them. Although I already believed that pregnancy begins at implantation, this was a bit of information that helped me put any of my remaining doubts/worries about the "abortifacient" question to rest.

@sparks : I am not trying to convert you, Sparks, if you still disagree with this interpretation of information. I would never want for you to be ill at ease with your conscience, either way. Good luck with your choice!

@ everybody! : Does anybody remember where this study was from?? I will try to find it. I hope am remembering that fact correctly and not misrepresenting it. Please jump in and correct me if I have misremembered/misrepresented anything. I know there are more avid and attentive study readers here on our board!
(Deleted comment)
Aug. 31st, 2011 12:32 am (UTC)
I don't have the info. to hand but I'm sure I read somewhere that a not insignificant number of fertilised eggs never make it as far as being implanted anyway and the body just "rejects" them. That might make you feel a bit less worried about the "life begins at fertilisation" thing. I.I.R.C., it's thought that the body naturally chooses not to continue with what would ultimately not be a healthy pregnancy because of poor egg or sperm quality.
As I said, I can't back this up right now but I'm sure someone will shoot me down if I'm hideously misinformed.
Aug. 31st, 2011 04:12 am (UTC)
Here's a comment in vaginapagina where ArchangelBeth breaks down current research: I've been meaning to put those links up in this comm.
Aug. 31st, 2011 04:14 am (UTC)
Er, current research on how Cu IUDs work, that is.
Aug. 31st, 2011 01:30 pm (UTC)
Thank you all for the comments! I never really considered it to be aborting anything but wanted to be 100% clear on how it operates. Thanks again, I really appreciate it!
Sep. 1st, 2011 12:13 am (UTC)
Copper is toxic to both gametes, my theory about how copper IUDs work - as soon an an egg pops out the ovary and is grabbed by the fallopian fimbrea it is going to bathed in copper ions of the fallopian tube/uterine lumen http://en.wikipedia.org/wiki/Lumen_%28anatomy%29

As toxic as we all know copper is to sperm, no one seems to thinks that an egg bathed in copper ions for days would be just as incapable of being fertilized, as the sperm are to fertilize it. If you can kill sperm in minutes of them being exposed to copper, how well do you think an egg fairs when it's been exposed to the copper for days?

Copper ions disable BOTH gametes - another reason why the failure rate of copper IUDs are so very low.

Also - There are some very old and out dated studies about copper IUDs and being able to flush out fertilize eggs from rabbits/guinea pigs and such. And also tons of anecdotal evidence of women getting pregnant with an old copper IUD.

One of the reasons why old copper IUDs were ‘retired’ because they did not have enough copper in them to kill the sperm and disable the egg from being fertilized. (The Dalkon Shield scandal didn't help matters either!)

And that’s the primary action by which it works – IUDs in the 60′s to late 80′s had highly variable amounts of not enough copper. IUDs nowadays almost ALWAYS contain 300+ square mm of copper. The current copper IUD approved by the FDA in the US contains 380 square mm of copper. (Just like you I had to research this myself. Try using http://scholar.google.com/ for research, it rocks!)

I don’t think copper IUDs are abortifacients when they have this much copper in the to disable BOTH sperm and egg!!! But I could see how low copper levels in the original IUDs would have lead to this belief.

Good luck.

Ps - Extra reassurances . . . .

The Reproductive System at a Glance
By Linda J. Heffner, Danny J. Schust

The copper ion competitively inhibits a number of zinc-requiring processes in sperm activation and endometrium/embryo signaling.

The influence of copper on the in vitro motility of the human Fallopian tube.
by Larsson B, Ljung B, Hamberger L.

High concentrations of CuCl2 produced a marked initial increase in frequency, but the rhythmic activity was soon abolished. An influence of copper on the motility of the human oviduct has to be considered as a possible factor contributing to the contraceptive action of the Cu-IUD.
*Copper first produces cramps and then abolishes them, messing up the timing of sperm meet egg.

Review on copper in male reproduction and contraception

Copper reduces the oxidative processes and glucose consumption, which reduces or abolishes mobility (in sperm): this property is exploited in intrauterine devices.

The mode of action of IUDs.
Contraception. 1987 Jul;36(1):37-53.

NORMAL FERTILE CYCLE - 6 to 57% incidence of fertilized ova that did not result in pregnancy.

With an IUD in place, several searches recovered no sperm in the tubes, presumably they were phagocytosed -eaten by macrophages-.

Copper IUDs especially reduced numbers of sperm, and those found often had heads decapitated from tails.

Ovum migration in IUD wearers was not appreciably affected through the oviduct, but few eggs were found in the uterus, again far fewer were found in copper IUD users. Looking at ova that were detected in IUD users, none were developing normally, the rest were classified as either abnormal or uncertain. Ova from copper IUD users were distinctive for being without vitellus -the yolk of the egg- and surrounded by macrophages.

*This preliminary research as a whole suggests that IUDs affect events prior to implantation, specifically ovum development in the tubes, sperm migration, and ovum transport in the uterus.
May. 14th, 2012 07:20 am (UTC)
I'd love to link to this comment (and whole post) from VP and elsewhere, but for some reason, sparks_electric (and I) can't make the post visible to everyone. Do you mind if I copy-pasta the comment in VP whenever someone asks how IUDs work? (With attribution, of course.) So far, I've done so once, and only copied the sources and abstract summaries.
May. 14th, 2012 05:50 pm (UTC)
Copy and paste away, this journal entry should be viewable by all but if LJ is being wonky spread the info any way you can!
Sep. 1st, 2011 12:13 am (UTC)

Copper ions that spread into the fallopian tubes also inhibit acrosomal enzyme activation. Without the acrosomal enzymes, the sperm are unable to penetrate the zona pellucida. Ova fertilizablitily is also reduced due to increased prostaglandin peritoneal levels, probably induced by copper.

New insights on the mode of action of intrauterine contraceptive devices in women. Fertil Steril. 1988 May;49(5):768-73.

In another study, washings from the uterus and uterine tubes of women undergoing surgical sterilization were examined at midcycle. Ova were recovered from the uterine tubes of 39% of IUC users (30% of copper-containing IUD users) and 56% of the women who were not using IUC.
Of the eggs recovered from women who had intercourse prior to the procedure, 64 percent showed a lack of normal preimplantation development, compared with 19 percent of the eggs from women not using a device.

Basically copper completely disrupts the signaling between egg, the tubes, the uterus, the sperm and it disables BOTH sperm and egg.
May. 13th, 2012 07:04 am (UTC)
So this post is full of super helpful information, but not so helpful if you're not an iud_divas member because it's friendslocked. Do you feel comfortable making the post visible to everyone?
May. 13th, 2012 07:57 am (UTC)
I tried to change it to public but it gives me an error message so I can't. :-/
May. 14th, 2012 07:18 am (UTC)
Damn! Maybe something strange is up with Livejournal. Thanks for trying, though.
May. 15th, 2012 08:07 am (UTC)
I managed to unlock the entry so it's free for all to see now. :-)
( 21 comments — Leave a comment )