Miscarriages (including the MTHFR Gene)

Why is this Gene Important?

This gene controls one of the body’s key functions and when it mutates this leads to problems. There are two common mutations of the MTHFR gene called C667T and A1298C. In one study more than half the US population had one copy of the C667T mutation and 10% had two copies (homozygous). When there are two mutations then gene activity can be reduced by half.

When this happens one of the basic processes of the body, methylation, is slowed down. This leads to a reduced ability to produce glutathione (the key substance in detoxification) and problems processing folic acid and repairing genes. In particular it makes converting folic acid to its active form, methylfolate, difficult.

Where does this make a difference?

It plays a part in a range of diseases but probably the most important is recurrent miscarriages. One issue here is that folic acid is given in pregnancy and this can make the situation worse as people with this gene mutation find it difficult to process synthetic folic acid. They need to use methylfolate instead of folic acid and sometimes methylcobalamin (the methylated form of vitamin B12). These mutations are commoner in many auto-immune diseases and can also be a factor in anxiety. It can predispose to pre-eclampsia and birth defects.

What’s to be done?

Genetic testing isn’t normally available on the NHS. It would be sensible for anyone with a history of miscarriage to change the form of folic acid that they use in pregnancy.

Other Nutrients

        High homocysteine is also linked to higher rates of miscarriage. Common reasons for this are deficiencies in folate and Vitamin B12. Hyperhomocysteinemia and recurrent early pregnancy loss: a meta-analysis. Fertil Steril, 2000; 74(6): 1196-99

        Lower levels of both Vitamin C and E have been noted in those with recurrent miscarriages. Clin Chim Acta, 2000 May;295(1-2):169-77. doi:10.1016/s0009-8981(99)00255-7.

The Vitamin E Studies

        In 1931 wheat germ oil was found to stop recurrent miscarriages. By 1937 the Shutes in Canada and Young in England were preventing miscarriages with Vitamin E. Barcharach in 1940 did statistical analyses which found Vitamin E was of value in recurrent miscarriage and by Word War II many studies confirmed this. Take 200 or 400 IU of either D alpha tocopherol or mixed tocopherols (not the synthetic DL alpha tocopherol).

Antidepressant Drugs

        A Canadian study looked at the use of antidepressants during pregnancy and found those using these drugs had a 68% greater chance of miscarriage. This was highest with SSRI anti-depressants (61%) and venlafaxine (271%).


        This infection can cause miscarriages. The main source is cats, or to be specific, cat faeces.


        Progesterone is produced by the corpus luteum in the ovary. During pregnancy levels of progesterone rise and after ten weeks the placenta takes over the production of progesterone. However if progesterone is low the lining of the uterus will be thin (luteal phase defect). This makes miscarriage more likely. A clue to this would be a history of premenstrual tension (PMT). (PMT)https://pubmed.ncbi.nlm.nih.gov/28277122/#:~:text=Gynecol%20Endocrinol,2017%20Feb%2028).

        Good nutrition is critical to producing enough progesterone. For instance Vitamin B6 helps increases progesterone and also reduces the risk of miscarriage: https://pubmed.ncbi.nlm.nih.gov/17478435/#:~:text=Am%20J%20Epidemiol,Epub%202007%20May%202. Vitamin C has also been shown to increase progesterone and reduce miscarriages: https://pubmed.ncbi.nlm.nih.gov/12909517/#:~:text=Fertil%20Steril,0282(03)00657%2D5. Other nutrients such as zinc, magnesium, Vitamin E and L arginine can help increase progesterone.

                For this reason there is a strong case, in recurrent miscarriage, for having an “overdose” of good nutrition such as plenty of fruit and vegetables, seeds and nuts, green juices, herbs and spices and removing harmful foods (sugar, refined carbohydrates, processed foods, chemicals, preservatives and artificial sweeteners).


        Patients with the highest levels of bisphenol A were 80% more likely to miscarry. (Bisphenol A is found in hard plastics. A particular problem is cans as BPA is used as a liner and it migrates over time into the food). However this study is likely the tip of a large iceberg as many pollutants are known to cause miscarriages in animals. Some form of detoxification (see toxicity leaflet) would seem a sensible measure in those with miscarriages.

Low Thyroid

        In the book Thyroid Power the authors note that low or borderline thyroid can be a cause of recurrent miscarriage. They claim that they have seen this several times. They give a case report of a lady with two previous miscarriages. Her thyroid test showed borderline TSH of 3.0 (this would be regarded as normal in the UK) and borderline low T3 but positive thyroid antibodies. However she had classic hypothyroid symptoms of low energy, dry skin and being chilly much of the time. After starting thyroid hormones she went on to have a normal birth.

        A review of the literature by Sarkar in 2012 found that even minimal hypothyroidism can increase the rates of miscarriages and that there is a significant relationship between thyroid antibodies and a higher miscarriage rate.     Sarkar D. Recurrent pregnancy loss in patients with thyroid dysfunction. Indian J Endocrinol Metab. 2012 Dec; 16(Suppl 2): S350–S351. doi: 10.4103/2230-8210.104088



        A study in 2010 found undiagnosed gluten sensitivity can be a cause of recurrent miscarriages:  https://dx.doi.org/10.3748%2Fwjg.v16.i46.5810

What else?

There is a known link between miscarriages and electromagnetic radiation and makes sense for anyone in pregnancy to keep their exposure to mobile phones, wifi, DECT phones and smart meters to a minimum. Electric blankets have been linked with miscarriages. Exposure to electromagnetic fields from mobile phones has been found to increase the possibility of miscarriage three-fold.

Having enough time between pregnancies is also vital. We know that in healthy long-lived societies they would leave a gap of two years between pregnancies (presumably to build up nutrients) and eat more of the high nutrient foods during this time.

A wide range of chemicals has been found to increase the rate of miscarriage. Remember anything put onto your skin is absorbed into the body as is anything you can smell (such as aerosols).

It is interesting that night-shift workers have an 85% higher risk of miscarriage, suggesting adequate sunlight is important.