MTHFR Support

How can MTHFR Affect your Fertility?

How can MTHFR Affect your Fertility?

I have seen many patients with the MTHFR gene mutations and overwhelmingly they present with multiple miscarriages and failed IVF procedures. Often, they have been to multiple doctors, multiple clinics, multiple naturopaths and nutritionists but they cannot fall pregnant or hold a pregnancy. Why?

Well mostly it’s because they lack active folate. Remember that active folate is essential for good DNA and the key reason they are having miscarriages and not falling pregnant is because you need active folate to have good hormones and you need it for good DNA in the sperm and the egg. If you don’t then the body says “this is not a viable pregnancy, I’m going to get rid of it”. Its natures way of helping us deliver healthy babies.

Its crucial though to make sure that both Mom and Dad are checked for the MTHFR gene. 

The diagram below shows us that the folate from your food, represented by the ‘DHF’ (dihydrofolate), must be converted via many steps down into your active folate, 5-MTHF.

You can see the MTHFR enzyme comes in at this last step of the process. This means, that if you have a mutation in your MTHFR gene, the ability for your body to create healthy levels of active folate will be affected or decreased. This will result in less active folate available for your body to use in several very important processes.

This is where the link between MTHFR gene mutation, preconception and pregnancy arises. Several of the vital processes that we need active folate for are highly active during times of preconception and pregnancy and need to be working well to support a healthy pregnancy.

During preconception and pregnancy, you need good levels of active folate for:

  • Creating healthy DNA for both you and your future child. This is the biggest reason why knowing your MTHFR gene result is so important. Active folate is directly involved in the synthesis of new DNA. And while we have a constant demand for the production of new and healthy DNA, you can imagine that demand for this hugely increases during pregnancy, when you are growing a new life! Issues with not enough healthy DNA available for both mother and growing child can result in issues with pregnancy, fetal growth, and general childhood development.
  • Preventing levels of a substance in the body called homocysteine from climbing too high, which can be related to blood clots and increased risk of blot clot formation during pregnancy.
  • To create molecules called ‘methyl groups’, which act as instruction manuals for your DNA and cells, telling them the correct way to ‘behave’, so they do not do anything unwanted (e.g. cause disease or dysfunction within the body). We need healthy levels of these methyl groups to methylate/instruct your DNA, and without it cells are uncontrolled and can start to cause problems.
  • Formation of red blood cells, white blood cells, and platelets, which are all vital for both the health of the mother during pregnancy and also for the health of the child during pregnancy and after birth as they begin to rapidly grow and come into contact with bacteria and pathogens to strengthen their immune system.


Below I have broken down the latest research on the three most common pregnancy-related issues associated with MTHFR genes, and explain just how these important genetic mutations could be playing a role.

1. Recurrent Pregnancy Lost (RPL)

In the world of MTHFR and fertility, it unfortunately isn’t uncommon to hear many stories of women dealing with recurrent miscarriages.

And while science is still working to unearth the key role MTHFR is playing in RPL, it does understand the role your MTHFR gene plays in ensuring your levels of homocysteine do not elevate too high.

Homocysteine is an amino acid (small protein) that in excessive amounts can cause blood clots.

And while the jury is still out, some scientists have put forward the hypothesis that these blood clots may form close to the placenta, causing a block in the flow of nutrients to the fetus in it’s early stages of growth.

There are several key genetic mutations that have been associated with an increased risk of clot formation, with the MTHFR genes being some of them. And while studies tend to examine these genes in isolation, one study looked at the effect of these genes in unison and found the cumulative effects of multiple genetic mutations (such as Factor V Leiden and MTHFR) are indeed risk factors for RPL.

This study also found that women suffering from RPL were more likely to carry a homozygous mutation, that is, two copies of a genetic mutation as opposed to one copy, or no mutated copies.

The good news is more and more doctors, specialists and health practitioners are starting to test women who have either a family history of thrombophilia’s or who are experiencing RPL for these clotting related genes. The normal recommendations within the medical field to support these genes is to prescribe folate, B Vitamins and anti-clotting medicines like heparin or baby aspirin.

2. Preeclampsia

Both variants of the MTHFR gene, A1298C and C677T, have been implicated in preeclampsia, with different studies yielding differing results.

Research has found mutations to the MTHFR A1298C gene to be significant risk factors for several vascular-related pregnancy complications. In this paper, researchers found significantly higher plasma homocysteine levels and increased risk of premature separation of the placenta from the wall of the uterus, smaller fetuses, recurrent pregnancy loss, and preeclampsia among pregnant women with MTHFR A1298C mutations.

Another study found women with preeclampsia in their first pregnancy are also more likely to have MTHFR A1298C mutations, higher homocysteine levels, and babies with lower birth weights.

However, the MTHFR C677T variant has also been implicated in preeclampsia, with women suffering from preeclampsia more likely to be carrying a homozygous MTHFR C677T mutation (meaning two copies of the mutated gene). So while these studies have examined different MTHFR genes and aspects of pregnancy health, both C677T and A1298C variants have been shown to play roles in complications during pregnancy.

3. Fetal Developmental Disorders

The foundational reason MTHFR mutations require our acknowledgment and support, whether pregnant or not, is due to their vital role in creating active folate, which we need for cell division and healthy DNA production. Why is MTHFR important in preconception and pregnancy? Read more about that here.

Having healthy levels of DNA during pregnancy has clearly been linked with the prevention of developmental problems including neural tube defects such a spina bifida and anencephaly.

And while these links are common knowledge within the medical sector, research now also shows:

While science still needs to definitively show MTHFR as a true cause in many of these conditions, there can be no doubt MTHFR is highly suspect in RPL, preeclampsia, and other pregnancy complications.

With this in mind, the best advice I can give to women who are pregnant or preparing for pregnancy is to strongly consider screening yourself and your partner for the MTHFR gene and other clothing factors if appropriate.

And always remember, if you do have a genetic mutation in the gene, Carolyn is the leading fertility expert in this field and has written a course specifically for those with the MTHFR gene that you can access here.

As you can see, addressing and supporting your MTHFR genes during your preconception phase is the best way to healthily support both your body once you fall pregnant, and the growth and development of your new baby.

Knowing your MTHFR gene result and supporting your folate levels where needed is a key step in preconception, and both should not be undervalued!

If you would like to check if you have the MTHFR gene click here

If you would like to listen to my webinar on fertility, click here

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Carolyn Ledowsky

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