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Seeking Health we will be closed on May 27th in observance of the holiday. We will resume normal business hours on May 28th.

Recurrent Pregnancy Loss and MTHFR

Recurrent Pregnancy Loss and MTHFR

Recurrent miscarriage can definitely be associated with MTHFR, but even with recent research, it is not always easy to find a doctor who is well-versed in this connection.

Does this sound familiar?

“I was just told by my high-risk OB that there is no research proving MTHFR is connected to miscarriage.”

If you’ve been told that before, unfortunately, your OB is not up-to-date on MTHFR education. It is actually well-documented that MTHFR is associated with miscarriage.

When it comes to miscarriage or repeated pregnancy losses, not only are you experiencing tragic loss, you are also faced with unanswered questions about how to solve this medical situation and prevent further losses. It is an emotionally charged issue that is multifaceted and layered with numerous factors to consider.

Treating recurrent miscarriage is not a simple matter, yet many doctors approach it as if it were.

Hopefully, you do not feel alone in this journey and are not left to your own devices to find answers. Sadly, however, that is the case for many women experiencing repeated pregnancy losses. If you have come here today looking for answers, I hope to give you the information you need to ask questions of your doctor and, if necessary, find one who is well-versed in this subject.

Genes and Recurrent Pregnancy Loss

If you ask a high-risk OB, they might be inclined to say that the number one genetic problem associated with pregnancy loss is Factor V Leiden, or F5 as it is known. For the longest time, this was the truth. However, in recent years, only one gene has surpassed Factor V Leiden in being associated with pregnancy loss.

You guessed it, it’s MTHFR.

The Centers for Disease Control and Prevention are one of many credible sources used in medical research. According to them, 93 studies and six meta-analyses have been tied to MTHFR, whereas 81 studies and three meta-analyses are associated with Factor V Leiden and miscarriage. (1)


In the last seven years, MTHFR has overtaken Factor V Leiden as the most-associated with miscarriage.

MTHFR and Recurrent Miscarriage

There is no doubt that MTHFR and recurrent pregnancy loss are linked. This is especially true if you have:

  • 1 or 2 copies of C677T
  • 2 copies of A1298C
  • 1 copy each of C677T and A1298C

If you only have one copy of A1298C, research isn’t clear whether or not this will impact your pregnancy outcome, but I am on the fence about ruling it out as a potential risk factor.

Before we discuss protocols, I first want to cover the traditional medical standard of care for pregnancy loss and MTHFR. While I am not an OBGYN or a specialist in recurrent miscarriage, recent research is very clear on standard protocols for MTHFR: (2)

  • Baby aspirin
  • Heparin
  • Folic acid

Most patients, after finding out that they have one or more MTHFR mutations, are told to take higher amounts of folic acid.

This, however, is a mistake from the standpoint of healthy methylation. Doctors should instead be prescribing and recommending methylfolate and folinic acid to pregnant women, not synthetic folic acid.

This is partially because there is some conflicting evidence regarding MTHFR and recurrent pregnancy loss. As with most research, there is some that definitely says one thing, and something else to contradict it.

Why can there be contradictory results, especially when it comes to MTHFR and miscarriage?

Research studies can be extremely thorough, but it would be hard to test for every variable that influences methylation and genetic health. Some women with MTHFR mutations could be consuming plenty of leafy greens, avoiding folic acid, and taking active forms of folate. Their methylation cycles are working well and their risk for miscarriage would be lower.

Others, however, could have MTHFR mutations and be taking folic acid, eating a diet low in folate, and living a stressed and chaotic lifestyle that places burden on their genes and their methylation.

Yet, from a research standpoint, they have the same “condition.”

Just because you have a MTHFR mutation does not guarantee that you will have recurrent losses, but it does say—with plenty of research—that the risk for miscarriage is increased. (3)


How Much Methylfolate for MTHFR and Pregnancy Loss?

The question of how much methylfolate and/or folinic acid is needed does not have a straightforward answer as there is no set guideline that applies to everyone. Women new to methylfolate need to taper up, and anyone taking it short or long-term should have levels tested to assess the various forms of folate.

The primary reason why folic acid is a bad idea in any pregnancy, but especially recurrent miscarriage, is that folic acid is an inactive form and requires enzymatic conversion. If someone has any MTHFR mutation, they have an impaired ability to turn this into the active form, resulting in low levels of bioavailable folate. This can be true no matter how high the dose is of folic acid.

Proactive doctors who are up-to-date on the latest research know that folic acid is a cause for concern, both for miscarriage risk and for normal fetal development. Folate is essential in the first few weeks following conception to prevent neural tube defects. Even women without a history of miscarriage or MTHFR need active forms of folate to nourish the developing baby. Folinic acid and methylfolate are the two types that should be prescribed for pregnancy.

When it comes to standard protocols for recurrent miscarriage, whether MTHFR and other clotting factors are present or not, a common standard of care can be to prescribe baby aspirin and heparin or lovenox, to thin the blood and reduce the risk of clotting. (4) While these can sometimes be successful at treating recurrent pregnancy loss, there is sometimes more to the picture.

I’ve been educating patients and practitioners alike on MTHFR since 2011. I have so frequently heard the following:

“My OB tells me that MTHFR is a variant akin to having eye color differences, and does not require treatment. But I’ve had six miscarriages and since starting methylated vitamins, have had three healthy pregnancies.”

No, everyone who has MTHFR will not have a miscarriage and may not show signs of needing methylation support. However, it is also not universally true that it never needs treated.

What to Do If You’re Having Recurrent Pregnancy Loss

Women who present with recurrent losses should be further evaluated. Doctors should be asking:

  • What other relevant blood tests could be done?
  • Does the woman’s partner have genetic or clotting disorders?
  • What are both the father’s and the mother’s lifestyle and dietary choices like?
  • What is their occupation?
  • What are their common environmental exposures?
  • What are their stress levels?

Unfortunately, many doctors don’t ask these questions, which leaves patients to do their own research and stumble into finding their own answers for these questions.

It’s essential to thoroughly evaluate the woman’s genes and overall health, but discounting her partner’s health leaves room for missing as much as 50 percent of the reason for recurrent losses.

If you are working with a doctor who is not being proactive in addressing known and potential causes of recurrent loss, it is time to educate them on MTHFR and what you have learned here. It could also be that it’s time to find a new doctor who is already well-versed in this subject.

Bottom Line

If you are having recurrent miscarriages, consider doing genetic testing along with your partner. Check first for MTHFR and Factor V Leiden.

If you have not yet done personalized genetic testing, consider using the StrateGene test kit to get a full methylation analysis of you and your partner.

Remove all folic acid, from foods and supplements, and focus on eating foods rich in natural folate. Supplement with high-quality folinic acid and methylfolate on their own or take a prenatal vitamin that supplies both.

Learn more about the science of why folic acid is so harmful. 

Please share your experiences of recurrent pregnancy loss below:

  • Has your doctor been proactive when it comes to MTHFR, or underactive?
  • What was done medically and/or nutritionally to support your pregnancy so you could carry to term?
  • If your doctor was proactive and you had a successful pregnancy, feel free to share your doctor recommendation.

Expand your learning of MTHFR and Pregnancy by reading the most thorough post on MTHFR and Pregnancy Loss.



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