Copper coil - how often does it prevent pg by preventing implantation?

[harrowgreen]

Am 30wks with #3. Currently not planning any more but unwilling to go down the road of sterilisation yet.

Don't want contraception involving hormones or a barrier method so am debating the copper coil (IUD). However all the info I've read talks about how it 'may' also work by preventing fertilised eggs implanting.

This is a big deal for me. All three of our children were conceived immediately we tried (two of them were one shot wonders, the other took three (consecutive) days) so we're clearly very very fertile. Secondly, I've known with each that I was pregnant by about 3dpo (ie pre-implantation) - I get morning sickness from then until 11wks. Thirdly, I believe that life begins at conception.

As a result, I'm very loathe to use a form of contraception which could work by preventing implantation: I don't want to repeatedly feel/know that an egg has been fertilised and then know that it will be prevented from implanting. That would feel like an abortion to me.

So does anyone know how often the copper coil works by preventing implantation as opposed to preventing the egg and sperm meeting in the first place?

[DayLillie]

From:
cks.nice.org.uk/contraception-iusiud#!scenario:1

Mechanism of action

The primary mode of action of copper intrauterine devices (IUDs) is via the toxic effects of copper on the ovum and sperm, preventing fertilization.
In addition, alterations in the copper content of cervical mucus may inhibit penetration by sperm, and inflammatory reactions within the endometrium may prevent implantation, should the ovum be fertilized [Stanford and Mikolajczyk, 2002; FFPRHC, 2004a]. Consequently, the copper IUD can work immediately after insertion.
A judicial review ruled that pregnancy begins, not at fertilization, but at implantation; thus the copper IUD is not legally considered an abortifacient [DH, 2002].

[Jessbags001]

There just aren't any contraceptives, except barrier and NFP methods, that you can guarantee won't be abortive or interfere with implantation. The copper coil is no exception as it will render the uterus inhospitable in the event that an egg does get fertilised. Fertilisation may never happen, but that's not enough when it's a moral issue for you.

What about a diaphragm? Or a combination of condoms/diaphragm with natural family planning? It's pretty effective when done properly (but granted not very spontaneous or hassle-free!)

[harrowgreen]

Thanks.

Day - it sounds like the coil works reasonably often by preventing implantation then: every reference to the coil refers to it!

Jessbags - not keen on NFP (when I came off the pill and tried to check my cycles were back on track before TTC it drove me batty). I have been mulling over the diaphragm and although it'd be messy, it'd be better than condoms I think.... Starting to seem like the best/only option really.