Taken from a post written in November of 2008. Some additional information/links have been added.
I've seen many posts on the online forums which I visit and have received questions from many others about the MTHFR genetic mutation. This is my perspective.
Disclaimer: PLEASE consult your own medical professional and do not consider my thoughts and opinions in your own treatment. Everything included herein is not based on information from a medical professional. (I am an elementary school teacher!!) Everything written here is based upon MY personal experience and research. I cannot/will not be held liable for erroneous information or for those seeking answers or treatment.
MTHFR - methylenetetrahydrofolate reductase - is a gene that we ALL have. So if someone says "I have MTHFR," of course they do! However, some of us unfortunately have mutations of the MTHFR gene which can cause miscarriage and Recurrent Pregnancy Loss. The MTHFR mutation causes the body the inability to absorb folic acid (vitamin B9) and may also cause clotting issues, both of which are vital for a successful pregnancy. It is possible to carry a successful pregnancy with the MTHFR mutation, but the risks are higher for cystic fibrosis and other neural tube defects due issues with folic acid deficiencies.
There are a couple of basics of the MTHFR mutation/diagnosis. There two genetic mutations of the MTHFR gene. The first is of the C677t gene and the second is the A1298c. There are homozygous (2 copies) and heterozygous (1 copy) mutations of the gene, and each can create different issues depending on the type of mutation one carries. Recurrent Pregnancy Loss panel (see below) results will show the exact mutation(s) although treatments are often very similar or the same.
Testing of the MTHFR gene is simple. One of the standard tests in the RPL panel includes testing of the MTHFR gene. This blood work can be drawn to test for many disorders which might explain RPL in some women. Many insurance companies will not cover costs of the RPL panel until three (3) or more miscarriages have been diagnosed. Check with your insurance company or "work" with your doctor for coding should you require/need/want RPL testing prior to three (3) miscarriages.
Very little information is available on the MTHFR mutation because it was discovered just a handful of years ago. There is some information available on the internet, but much of it is in medical journals which can be difficult to decipher and comprehend. The resource I have found to be the easiest to understand in my research is here. More information is becoming available about the mutation as more research is completed and more is learned. I've added some additional links I found at the end of this post.
* Typical protocol for treatment includes an increase in folic acid (appx. 4mg daily) , a daily dose of 81mg aspirin (the same dosage of baby aspirin), and the possibility of blood-thinning injections during pregnancy. Some doctors increase the intake of vitamins B6 and B12. Of course, all women trying to conceive should take prenatal vitamins - either prescription or over the counter. An OB/gyn should have patients do a fasting blood draw to test your homocysteine levels. If they are elevated, he/she will most likely prescribe Lovenox or Heparin shots upon a positive pregnancy test.
My diagnosis & treatment: After my first two m/cs (early, both at 8.5w), my amazing OB/gyn felt it would be smart for me have the RPL panel run. He :helped" (coded) my paperwork so that my insurance would cover the testing without question. I was found to have a homozygous MTHFR mutation of the C677t, which means that I have two copies of that gene. My Rx includes 4mg of a prescription folic acid each day, plus my PNV (which also contains f/a), and an 81mg aspirin each day. When tested, my homocysteine levels were not elevated, but my ob/gyn wants me to have Lovenox injections with my next bfp because (1) I've requested it because I feel in my gut that it will help, and (2) he's proactive and willing to "pull out all the stops" for me to have a successful pg. He's an awesome doc.
Hope that helps to answer some questions and provide information that might help you or someone else.
Other resources about MTHFR you might want to check:
Factor V Leiden - What is MTHFR?
Miscarriage on About.com