I've researched a lot about this. Did you know 40% of the population has one copy (or hetero) MTHFR?
I'm Homo (two copies) MTHFR but I also have Factor V, Pai-1 and Hashimoto's with extremely high anti-thyroid antibodies.
After close to three years of TTC and several early losses I finally left my clomid/IUI happy RE and found an OBGYN who would let me 'try' a few rounds of lovenox. (The RE would only let me try baby aspirin until confirmed pregnancy but I knew my issue was w/ implantation because I couldn't carry past 4 1/2-5 weeks, we never made it to 'heart beat')
On our 4th lovenox & femara (I O really late on my own without meds) cycle we got this sticky bfp.
Typically baby aspirin is the treatment if you only have one copy but if you feel in your heart you need more then I would push for it, even find a different dr if you need to. Pray on it, God will guide you like he did for me, on the best treatment.
Here is a website of ladies ttc w/ lovenox http://community.babycenter.com/groups/ ... enox_group
And here is a yahoo group for women TTC with immunology issues (MTHFR) would fall in that group, this site is cram packed full of info and led me on my search for the right treatment: http://health.groups.yahoo.com/group/immunologysupport/
Be proactive, learn every thing you can to arm yourself with the right questions to ask your dr. Don't just go along w/ what they say, you have to almost dr. yourself when it comes to this.
Good luck, if I can help PM me