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Old 04-15-2019, 04:28 PM
SenorBeef is offline
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Which contraceptive methods prevent fertilization entirely, and not just pregnancy?


I'm not making a value judgement on exact specifics of birth control. I am just saying, that in my specific case, I have an aversion to using my genetic material to create any sort of fertilized egg, and sort of new combination of DNA using my genetics. I do not want to create a new set of genes, even if it doesn't result in implanting and pregnancy. Why is irrelevant.

So I'm looking at options for birth control that prevent my sperm cells from ever reaching an egg, not just ensuring that it never develops into a pregnancy.

So, the methods:

Condoms - any sort of barrier methods obviously prevent the sperm from reaching the egg, so this suits my need. Also, they suck when using it in non-dangerous (potential STI) situations. I would like to move beyond this method.

Non-hormonal IUDs. Copper IUDs. In the US, apparently this is only one particular brand, Paraguard. My understanding is that the copper creates a hostile environment that reliably kill or otherwise disable sperm before they can potentially find the egg. I'm not sure if the copper IUD has any sort of way of preventing implantation or preventing pregnancy other than disabling the sperm. Does the 99%+ effectiveness rate come strictly from ensuring the sperm never get to the egg? If so, this may meet my requirements.

Vasectomy: This is probably the ideal option, since it's something I can do myself and not ask my partner to do. It's reliable and requires no effort once it's done. However, it's permanent. I'm very likely at peace with its permanent nature, but I'm kind of going through a weird transition period in my life right now, and I'm not quite 100% sure about that, so I hesitate to jump right to that option.

Related: I know you can pay a service to freeze your sperm for IVF in the event that you want to use it later to conceive. And that vasectomy reversal is effective in some cases. But... if the testes are still producing sperm, they're just cut off from the seminal fluid, why can't we go retrieve sperm from inside the testes, or the surrounding tubing for IVF? At least what I've read hasn't mentioned this as an option.

Various forms of hormonal birth control: This is mostly what I don't know about. I know there are multiple types of hormonal birth control. Multiple pills, shots that last a long time, patches, hormonal IUDs.

My understanding is that hormonal birth control has several mechanisms of action. It makes the various parts where the sperm have to travel a more hostile environment for sperm. It reduces the chances that an egg is "dropped" to be available for fertilization. And if sperm fertilizes an egg anyway, it hardens the uterus walls so that the newly fertilized egg can't implant in the wall and basically gets ejected/discarded. Is that correct?

Do all hormonal birth control medications work this same way? Are there some that reliably prevent fertilization in the first place and do not rely on ensuring that fertilized eggs do not lead to pregnancy after fertilization?

What degree of effectiveness does each effect have on preventing pregnancy? By this I mean, does the hostile uterine environment prevent 50% of pregnancies? 90%? Is it common for sperm to make it to eggs, fertilize them, but ultimately not result in pregnancy? Are some types of medications better at preventing fertilization in the first place?

As you can see, this concerns me because while I understand that most people don't care, I don't like the result of a fertilized egg being discarded, because I would strongly prefer not to fertilize an egg. So if some hormonal birth control reliably prevents fertilization, that's an option. But if some significant fraction of the time, it permits an egg to fertilize, and then only works by discarding that egg, that's not okay for me.

Other methods - I'm not familiar with other methods (other than less reliable ones like timing cycles and pulling out), but I'm open to be educated on them.

So please, educate me about birth control and specifically the differences between birth control that prevents fertilization and birth control that sometimes allows fertilization but prevents pregnancy.
  #2  
Old 04-15-2019, 04:44 PM
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Vasectomy: This is probably the ideal option, since it's something I can do myself ...
I would strongly urge you to have a licensed medical doctor do this!
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Old 04-15-2019, 04:49 PM
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Several other methods which prevent fertilization entirely, through a phyiscal barrier, but on the woman's side of things, are female condoms, diaphragms, sponges, and cervical caps. None of them appear to be widely used in the U.S. -- this article lists usage of various methods in the U.S., and all four of those are lumped into the "Other" category, which are used by less than 1% of contraceptive users.
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Old 04-15-2019, 04:51 PM
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I would strongly urge you to have a licensed medical doctor do this!
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Old 04-15-2019, 04:55 PM
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You've either got to stop the little buggers from going to work - condom. Or stop them from being created in the first place - vasectomy.

I gather that it is possible t retrieve some sperms from the testes after a vasectomy, but they will be few in number (note that there are millions in a normal ejaculation) and pregnancy from this would normally mean fertilising the eggs outside the woman. (in vitro). And yes - DIY vasectomy is not recommended.

Last edited by bob++; 04-15-2019 at 04:56 PM.
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Old 04-15-2019, 04:58 PM
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Abstinence.
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Old 04-15-2019, 05:04 PM
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You've either got to stop the little buggers from going to work - condom. Or stop them from being created in the first place - vasectomy.
A vasectomy doesn't prevent creation of sperm; they just can't get to work because you've blown up the only bridge into town.
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Old 04-15-2019, 08:29 PM
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Spermicides, although their reliability is lower than many other methods. They're best used in conjunction with another method.
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Old 04-15-2019, 08:30 PM
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Planned Parenthood has the basic answers.

The right answer for you really depends upon the strength of your desire to specifically not fertilize an egg, as opposed to simply preventing a pregnancy, and what degree of uncertainty you are willing to accept considering the strength of your aversion to causing fertilizaion. For example, abstinence will provide you with absolute, Cartesian certainty of not ever fertilizing an egg. Vasectomy is a close second, although to be really certain you would need to periodically have your semen re-evaluated, since delayed spontaneous vasectomy 'reversal' has been reported. A condom that you apply, remove, and dispose of yourself is your third best option, although the failure rate for condoms is relatively high. Injectable polymer to reversibly block the vas deferens and/or male hormonal birth control are still in the development pipeline.

All other methods rely on the actions of another fallible human person, which introduces one layer of uncertainty, along with the uncertainty inherent in the particular method. So, for example, the Nexplanon contraceptive implant failure rate is reported as 0.05%, but the outcome being reported is pregnancy. It is almost certain that ovulation and fertilization do not occur while the implant is in place, but there is no reported breakthrough ovulation rate. Once the implant is in, there are no questions of medication compliance, etc. An IUD is also quite effective at preventing pregnancy, but for example the copper IUD does not prevent ovulation, so its action is either by blocking sperm or preventing implantation. Most probably by blocking sperm, but not with mathematical certainty.

For oral hormonal contraceptives, the uncertainty over whether the method prevents ovulation/fertilization vs. implantation is practically swamped by the uncertainty over whether the pills have all been taken correctly, with no other medication interactions or food interactions, etc. etc. It's why real-world failure rates are 9% as opposed to a theoretical <1%. What's better from your POV: a method that is 100% effective at preventing pregnancy over a year but results in 13 fertilization events without implantation, or a method that gives a 9% chance of a single fertilization and implantation event over a year?

Furthermore, to what lengths are you willing to go to ensure that your sexual partner is using the 'right' form of contraception?
  #10  
Old 04-16-2019, 07:32 AM
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Only have oral or anal sex.
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Old 04-16-2019, 10:17 AM
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A vasectomy doesn't prevent creation of sperm; they just can't get to work because you've blown up the only bridge into town.
Not quite. I remember reading some time ago that when the tunnel (to use a more apt analogy) is blown, the sperm don't simply disappear but wander around your nethers looking for a way out. Since they are haploid and have had their genes stirred to boot, the body does not recognize them as Self and the immune system kicks in to defend you.

The article said that micro-surgery techniques had improved to the point where the tunnel could be restored reliably enough, but the sperm tended to be non-viable. This was not 100% -- the robustness of peoples' immune systems is variable, but vasectomies should still be considered to be irreversible.
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Old 04-16-2019, 10:51 AM
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How robust are sperms? If I store a few million in a nice sterile container in my freezer at -18C will they still be viable in a year; five years; how long?
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Old 04-16-2019, 10:53 AM
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How robust are sperms? If I store a few million in a nice sterile container in my freezer at -18C will they still be viable in a year; five years; how long?
"Honey? What's in this Tupperware in the freezer???"
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Old 04-16-2019, 11:15 AM
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"Honey? What's in this Tupperware in the freezer???"
"Fry it up and we'll see."
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Old 04-16-2019, 01:31 PM
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Immunocontraception. It's been done experimentally in dogs, rabbits, etc.
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Old 04-16-2019, 01:55 PM
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Only have oral or anal sex.
Trickle-down pregnancies are a significant risk for the latter.
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Old 04-16-2019, 03:20 PM
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Trickle-down pregnancies are a significant risk for the latter.
Is that so? I've never heard of that risk.
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Old 04-16-2019, 03:23 PM
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A vasectomy doesn't prevent creation of sperm; they just can't get to work because you've blown up the only bridge into town.
Nitpick: the only two bridges.
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Old 04-16-2019, 03:26 PM
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Is that so? I've never heard of that risk.
Experts say "not likely, but absolutely possible."
https://www.plannedparenthood.org/le...ause-pregnancy
https://www.healthline.com/health/ca...nant-from-anal
https://www.webmd.com/sex/anal-sex-health-concerns#2
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Old 04-16-2019, 03:46 PM
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I guess. But it seems like the same thing can be said about oral sex:

"Can I get pregnant from giving oral sex?"

"Yes, if the man withdraws from your mouth and ejaculates on your vagina"

But thanks for taking the time to find those links.

Last edited by manson1972; 04-16-2019 at 03:49 PM.
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Old 04-16-2019, 04:05 PM
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I guess. But it seems like the same thing can be said about oral sex:

"Can I get pregnant from giving oral sex?"

"Yes, if the man withdraws from your mouth and ejaculates on your vagina"
Well, true, though the vagina is considerably closer to the anus than the mouth is.

Also, never underestimate how clumsy or inaccurate a sexually-aroused person in a darkened room can be.

Possibly urban legend, but Dr. Ruth Westheimer, when asked how many sperm it took to cause a pregnancy, allegedly said, "just one quick one."
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Old 04-16-2019, 10:07 PM
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I would prefer methods in which user error isn't a factor. The most a appealing are hormonal IUDs, copper IUDs, and a Nexplanon implant. Depo shots are also an option but I'd prefer something removable in case of adverse effect from hormonal BC.

I tried reading some technical papers about these methods but I'm not sure I fully understand them. They also make it sound like we don't really know what percentage of times the BC prevented fertilization rather than preventing implantation.

I assumed copper was the best because it stopped sperm. But some of what I saw also suggests it ( rarely ) also stops implantation.

Which then makes me wonder - are hormonal methods more effective at preventing fertilization because they often prevent ovulation and egg availability whereas copper does not? Or is copper so much better at stopping sperm that it doesn't matter if ovulation occurs? I haven't found anything yet that conclusively answers this question.

Between a copper IUD, hormonal IUD, or Nexplanon implant, which is most likely to prevent fertilization?

Separate question: do hormonal IUDs have fewer side effects than birth control pills since they're delivered to the right area more specifically and presumably require a smaller dosage?

Last edited by SenorBeef; 04-16-2019 at 10:07 PM.
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Old 04-16-2019, 10:14 PM
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https://www.ncbi.nlm.nih.gov/m/pubmed/3311625/ it's a study that seems to address this question although it's 30 years old and I'm not sure I fully understand the conclusion.
  #24  
Old 04-17-2019, 10:04 AM
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I would strongly urge you to have a licensed medical doctor do this!
I was thinking the same thing.
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Old 04-17-2019, 10:34 AM
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Vasectomy: This is probably the ideal option, since it's something I can do myself and not ask my partner to do. It's reliable and requires no effort once it's done. However, it's permanent. I'm very likely at peace with its permanent nature, but I'm kind of going through a weird transition period in my life right now, and I'm not quite 100% sure about that, so I hesitate to jump right to that option.

Related: I know you can pay a service to freeze your sperm for IVF in the event that you want to use it later to conceive. And that vasectomy reversal is effective in some cases. But... if the testes are still producing sperm, they're just cut off from the seminal fluid, why can't we go retrieve sperm from inside the testes, or the surrounding tubing for IVF? At least what I've read hasn't mentioned this as an option.
As I mentioned to a friend of mine whose wife was regretting his vasectomy choice - "not to worry, they can harvest sperm. All they have to do is stick a big, long needle into your testes."

Birth control pills do allegedly prevent ovulation form happening at all. Of course, like all fire-and-forget mechanisms, nothing is 100%. Condoms leak, IUD's pop out, pills don't work 100% sometimes, foams and creams get sloshed out, diaphragms shift, the doctor "misses" or the tubes grow back together after a vasectomy or tubal ligation, etc. The only thing guaranteed 100% is either abstinence, menopause, or removal of the ovaries or testes - ie. the bits don't do what they should.
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Old 04-17-2019, 11:13 AM
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Possibly urban legend, but Dr. Ruth Westheimer, when asked how many sperm it took to cause a pregnancy, allegedly said, "just one quick one."
Isn't she the one who said that if you're using the rhythm method, the time to have sex was at the mid-point between periods?

Last edited by DesertDog; 04-17-2019 at 11:13 AM.
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Old 05-14-2019, 01:03 PM
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With sperm, it's a group effort - the first ones out of the gate break the enzymatic lining of the egg, lose energy to continue so they cannot impregnate, but if there's more sperms swimming in the back, one of them will find the eroded area of the egg and get in. This is why a high sperm count is helpful in impregnating someone. It's helpful to know also, the little fellas can live up to five days. A careless man would indulge five days prior to someone's ovulation and ovulation is not really certain all the time. This is why people using the rhythm method for birth control are called parents. With all of the certainty we know about sperm, snipping vas deferans is the way to go.
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Old 05-14-2019, 08:49 PM
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Which then makes me wonder - are hormonal methods more effective at preventing fertilization because they often prevent ovulation and egg availability whereas copper does not? Or is copper so much better at stopping sperm that it doesn't matter if ovulation occurs? I haven't found anything yet that conclusively answers this question.
I don't know the answer to any of your questions, but I wanted to make it even more complicated

Some contraceptives (I don't remember which) work mostly by preventing implantation. Ovulation works, sperm swim, fertilisation works -- and implantation fails.
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