Gluten and Infertility: the research and should you go gluten free?

One of my core recommendations as a fertility nutritionist is to adopt a gluten free diet if you are experiencing unexplained infertility and recurrent pregnancy loss, this is whether you are formally diagnosed with coeliac disease or not.  In my experience going gluten free has been the missing link that has helped many of my clients improve their gut health, bring down inflammation and reduce thyroid antibodies, all factors which significantly improve their chances.  

There have been several studies over the last 10 years linking gluten to infertility and recurrent miscarriage. This is because gluten is inflammatory for many people and can cause damage to the lining of the small intestine, which can lead to the development of coeliac disease (which can often go undiagnosed) as well as several other autoimmune issues that could contribute to infertility. 

Experts estimate that up to 80% of people with coeliac disease do not experience obvious digestive symptoms, resulting in the condition often remaining undetected. This was certainly the case with me, which is why I advise my clients with unexplained infertility and recurrent miscarriages to try a gluten-free diet for at least six months to see if it helps, although make sure you have been tested for coeliac disease before eliminating gluten from your diet. This is because if you have already taken gluten out of your diet, you may have a false negative test as you are not eating the food that is elevating your antibodies and triggering your immune system to attack the lining of your small intestine. 

Fertility specialists do not routinely test for coeliac disease until you have had several miscarriages, then they will test you for various autoimmune conditions. This is often when doctors uncover coeliac disease.

I am not suggesting that everyone who is trying to get pregnant needs to avoid gluten, as this is not the case. However, if you have been trying to conceive for a while, if you have been labelled as unexplained, or if you are about to undergo IVF, then trying a gluten-free diet to increase your chances would be a good idea. When your body is inflamed from gluten or other food intolerances, then the body is also in a state of stress, which alerts your body that there is an emergency going on and it is not a good time to get pregnant.

Here are some of the key findings from research on gluten and infertility: 

A study found that non-coeliac gluten sensitivity can induce malabsorption of key nutrients required for fertility such as iron, folate, zinc and vitamin B12. This is because inflammation of the lining of the small intestines caused by gluten can damage our enterocyte cells that absorb nutrients from our food, which leads to nutritional deficiencies (1)

With coeliac disease, a large percentage of the population often goes undiagnosed. Studies prove that gluten intake increases risk of spontaneous abortion, PCOS, endometriosis, low birth weight of the baby and reduced duration of lactation. 

Another study could detect a significantly increased prevalence (5.9%) of undiagnosed coeliac disease among women presenting with unexplained infertility. The findings suggest the importance of screening infertile female patients, particularly those with unexplained infertility, for coeliac disease. (2)

A 2014 study came to a similar conclusion. Physicians should investigate women with unexplained infertility, recurrent miscarriage, and intrauterine growth restriction for undiagnosed coeliac disease. Women with coeliac disease show an increased risk of miscarriage, intrauterine growth restriction, low birth weight and preterm delivery. However, the risk is significantly reduced by a gluten-free diet. (3) 

Another 2016 study found that up to 50% of women with untreated coeliac disease refer an experience of miscarriage or an unfavourable outcome of pregnancy. Despite this, coeliac disease is still little considered during the evaluation of infertility (4) 

A report studied the effect of coeliac disease and its treatment on fertility and pregnancy in 74 patients. Those on a normal diet had a shorter reproductive period, were relatively infertile, and had a higher incidence of spontaneous abortions than those on a gluten-free diet. Although maternal health did not appear to be seriously impaired by pregnancy in undiagnosed coeliacs, those on a gluten-free diet had significantly fewer symptoms and had heavier babies. (5)

A 2018 study found that prior to the diagnosis of coeliac disease, an increased risk of adverse pregnancy outcomes was seen, whereas after the diagnosis and the adoption of a gluten-free diet, no influence on reproductive outcomes was found. The study found that prior to being diagnosed, coeliac disease women have an extra risk of spontaneous abortion equal to 11 extra spontaneous abortions per 1000 pregnancies and 1.62 extra stillbirths per 1000 pregnancies compared to the non-coeliac disease women (6)

Some cases of infertility, IVF failure and recurrent miscarriage may be because of an overreactive immune system reacting to a high percentage of natural killer cells, which are linked to recurrent miscarriage and implantation failure. A study of natural killer cells in the lab and in mice found that exposure to gliadin (the protein in gluten) increased natural killer cell presence, toxicity, and activity. No researchers have conducted current studies on humans. (7)

Is it necessary for you to adopt a gluten-free diet? 

If your fertility issues are unexplained and you have been trying to conceive for a while without success, then removing gluten from your diet may be worth considering (after being tested and even if you don’t have coeliac disease). Especially if you have other underlying health issues going on, such as hormone imbalances, allergies, or digestive issues. If you are planning to go through a cycle of IVF, then it would be beneficial to go on a gluten free diet at least three months prior to the IVF treatment to reduce any risk of inflammation.

Testing for coeliac disease 

If you suspect you may have issues with gluten and you are still eating it daily, I recommend asking your doctor to test you for coeliac disease, the autoimmune condition that causes damage and inflammation to the small intestines following consumption of gluten. Autoimmune conditions put extra stress on the immune system and may well be affecting your ability to conceive and maintain a pregnancy. It is a good idea to rule out coeliac disease while you are still consuming gluten regularly, as this will enable the detection of coeliac antibodies in your blood test. It is harder to get a positive test if you are already avoiding gluten, which gives a false sense of security that gluten is fine for you.

An important point to remember is that many people are not actually coeliac, but gluten can still cause inflammation and damage to the body. This is called non coeliac gluten sensitivity. If your doctor has ruled out coeliac disease, but you still feel you are having problems with gluten, food intolerance testing through a practitioner like myself can be a good way to identify intolerances.  

The elimination test

If you are not keen on food intolerance testing, try going completely gluten free for four weeks and then reintroduce wheat bread daily for four days to gauge how your body reacts. If you have any noticeable symptoms, this is a sign that you need to eliminate gluten for at least six months, possibly longer. The only issue with doing this is that if you decide at a later date to have screening for coeliac disease, it may show up negative as you have been avoiding all gluten. So, I would recommend having tests for coeliac disease with your doctor first, and if it is negative but you still feel gluten is a problem, then do the elimination test. Coeliac disease affects a small percentage of the population, but a larger percentage experience symptoms of non-coeliac gluten sensitivity.  

Whether you have coeliac disease or non-coeliac gluten sensitivity, gluten is still damaging and putting stress on your body so avoiding gluten 100% is the key.

References

1. Bold J, Rostami K. Non-Coeliac Gluten Sensitivity and Reproductive Disorders. Autumn 2015. Vol 8 (4) 294 -297. Sourced from: www.ncbi.nlm.nih.gov

2. Choi Janet M, et al. Increased Prevalence of Coeliac Disease in Patients with Unexplained Infertility in the United States: A Prospective Study. Journal of Reproductive Medicine. May – June 2011, (56) 5-6: 199–203

3. Tersigni C, et al. Coeliac Disease and Reproductive Disorder: Meta-Analysis of Epidemiologic Associations and Potential Pathogenic Mechanisms. Human Reproduction Update, 2014. Vol 20 No 4 582–593

4. Casella G et al. Coeliac Disease and Obstetrical-Gynecological Contribution. Gastroenterol Hepatol Bed Bench, Fall 2016. Vol 9, Issue 4 241-249

5. Ferguson R, Holmes G K, Louke W. Coeliac Disease, Fertility and Pregnancy, Scand J Gastroenterol. Jan 1982. Vol 17, issue 1, 65–68

6. Grode L, et al. Reproductive Life in Women with Coeliac Disease; a Nationwide Population-Based Matched Cohort Study. June 15, 2018. Human Reproduction, Vol 33, No 8 1538-1547

7. Larsen J et al. Dietary Gluten Increases Natural Killer Cell Cytotoxicity and Cytokine Secretion. European Journal of Immunology, 10 July 2014. Vol 44, 3056 -3067