Understanding the MTHFR Gene and Its Impact on Fertility
Although the MTHFR gene test is not a routine part of standard blood work, growing research highlights its importance, especially for those facing fertility challenges. If you’ve experienced recurrent miscarriages, repeated implantation failures, or have a history of birth defects, testing for MTHFR gene mutations could be crucial.
Studies have shown that certain MTHFR polymorphisms are linked to increased risks of pregnancy complications. For example, specific mutations in the MTHFR gene have been associated with a higher likelihood of recurrent miscarriages and implantation failures. Identifying these mutations could offer critical insights into your fertility health and help tailor more effective, personalised treatment strategies.
In this blog post, we will explore what MTHFR means, delve into the current evidence, and outline the steps you need to take.
What Are MTHFR Mutations?
MTHFR stands for methylenetetrahydrofolate reductase, a gene that encodes the MTHFR enzyme, which plays a crucial role in processing folate—an essential nutrient in various body functions, including DNA synthesis and repair. This enzyme also converts homocysteine into methionine, a critical component in many biological processes.
We all carry two copies of the MTHFR gene, one from each parent. The most common variants of this gene are MTHFR C677T and MTHFR A1298C. Other rare MTHFR gene variants may also impact your health.
If you’re concerned about these rare variants, you must consult your doctor or genetic counsellor to understand what they could mean for your reproductive health.
MTHFR Mutation and Its Impact on Folate Metabolism
Individuals with MTHFR mutations, especially the C677T variant, may experience significantly reduced activity of the MTHFR enzyme. This reduction limits the conversion of folic acid and folinic acid into their active form, 5-MTHF, leading to lower levels of biologically available folate.
This decrease in 5-MTHF can reduce methylation capacity, elevate homocysteine levels, and increase the risk of neural tube defects (NTDs). Folate is one of the most critical nutrients for fertility and pregnancy, and proper folate metabolism is essential for lowering homocysteine levels, which, when elevated, are linked to adverse pregnancy outcomes and fertility issues.
MTHFR Mutation’s Effect On Female & Male Fertility
The MTHFR C677T variant has been studied in women undergoing IVF, revealing that those with this variant may require higher doses of ovarian stimulation medications and often present with higher basal FSH levels. This combination correlates with poorer oocyte prognosis during controlled ovarian hyperstimulation.
Conversely, another study indicated that the MTHFR C677T variant does not impact pregnancy rates or outcomes in women undergoing IVF/ICSI when sufficient folic acid supplementation is provided. This suggests that folic acid supplementation may be a more cost-effective solution than more expensive 5-MTHF, also known as the “activated folate”.
For men, a meta-analysis of case-control studies showed a significant association between MTHFR polymorphisms, mainly C677T and A1298C, and an increased risk of male infertility. This was especially prevalent in Asian populations, where these polymorphisms were linked with oligozoospermia and azoospermia.
The Importance of Proper Folate Supplementation
While research on the benefits of 5-MTHF supplementation for individuals with the MTHFR mutation continues, folic acid remains the only proven form of folate that effectively protects against neural tube defects (NTDs).
Global health guidelines recommend that all women trying to conceive take at least 400 mcg of folic acid daily to help prevent NTDs, even if they have an MTHFR variant, until the first three months of the pregnancy. Some individuals may also require higher folate supplementation, depending on their health profile.
Given the importance of proper type, dose and duration of folate supplementation, it’s crucial to consult a fertility dietitian who can assess your unique needs and provide tailored advice on the most appropriate supplement regimen.
Check out our previous blog for more information on different types of folate supplements supporting your fertility and pregnancy.
Bottom Line
- If you’ve experienced recurrent miscarriages or other fertility challenges, it might be worthwhile to consider getting tested for the MTHFR gene variant.
- Regardless of MTHFR status, folic acid supplementation remains crucial for preventing neural tube defects (NTDs).
- A fertility dietitian can guide you on the best supplement regimen tailored to your unique genetic profile, helping you optimise your fertility and supporting a healthy pregnancy.
