Gluten is a popular enemy these days. It’s blamed for everything from bipolar disorder to obesity. Look around online and you’ll find dozens of websites claiming that gluten causes infertility. These sites paint with a wide brush. Some imply that all or many cases of infertility are caused by gluten intolerance or undiagnosed celiac disease. There’s no research to support these gluten-causes-infertility claims on such a grand scale, but that doesn’t mean gluten isn’t to blame in specific cases. Researchers are looking at how undiagnosed celiac disease and non-celiac gluten sensitivity (or gluten intolerance) may be a part of unexplained symptoms and diseases, including infertility. Here are six possible ways gluten may be to blame for why you can’t get pregnant. However, it is clear that undiagnosed and/or untreated celiac disease can seriously compromise a person’s health. An estimated 1% of people worldwide are affected by this disease. (Some say this number is low due to undiagnosed cases.) Some men and women with celiac disease have symptoms that lead to a diagnosis early in life. Others show no symptoms or very vague symptoms. Diagnosis may be delayed (or never happen). Even without symptoms, a person’s small intestine and general health can still be affected by gluten if they have celiac disease. Untreated celiac disease has been associated with a number of health problems, including cancer, severe nutritional deficiencies, and infertility.
Undiagnosed Celiac Disease, Recurrent Miscarriage, and Infertility
Could infertility be one of the “vague” symptoms indicating celiac disease? According to medical research, it’s a possibility. One meta-analysis (a large study that analyzes many smaller studies) conducted in 2016 found that women with infertility were 3.5 times more likely to have celiac disease than those without fertility problems. Women with unexplained infertility were at even higher risk—6 times higher, in fact—of having celiac disease. Women who experience recurrent miscarriage may also be more likely to be diagnosed with celiac disease than the general population. A 2016 review points out that up to 50% of women with untreated celiac disease report having had at least one miscarriage or poor pregnancy outcome. One 2018 study in Denmark of over 12,500 women found that those with undiagnosed celiac disease were at increased risk of spontaneous abortion. However, women with celiac disease that had been diagnosed and treated did not experience higher rates of pregnancy loss. What happens in regards to pregnancy when those with undiagnosed celiac disease start a gluten-free diet? There aren’t many studies focused on this topic. In a letter to the medical journal Gut, a professor reported the case of four women, ages 28 to 39, who had experienced infertility for two to 12 years. After beginning a gluten-free diet, the women finally conceived. (The time period from starting the gluten-free diet to conception was between two and nine months.) In this group of four women was a 39-year-old woman who had been trying to conceive for 11 years. She had experienced several failed IVF treatments. After starting the gluten-free diet, she conceived nine months later. That first pregnancy ended too soon, but finally, two years after diagnosis and starting the diet, she delivered a healthy baby. In another very small study, four women with previously unexplained infertility were diagnosed with celiac disease. They all started a gluten-free diet. One patient conceived without fertility treatment just one month after changing her diet. A second patient required surgery to remove a rapidly enlarging fibroid. One month after surgery, she was diagnosed with celiac disease and started a gluten-free diet. She conceived naturally four months after the surgery, three months after starting the diet. The third patient conceived with gonadotropins and IUI eight months after celiac diagnosis and diet change. The fourth patient conceived ten months after diagnosis and diet change via a frozen embryo transfer. These case studies don’t offer strong enough evidence to say a gluten-free diet was the cause of their pregnancy success. Clearly, sometimes the diet wasn’t enough. Some required surgery or fertility treatment, possibly in addition to the diet change. Still, it’s interesting. Especially when you consider that studies looking at those with known celiac disease — who are already on a gluten-free diet — seem to find that they are not more likely to experience infertility than the general population. Researchers aren’t sure if non-celiac gluten sensitivity (NCGS) is one condition or possibly a part of several conditions. Of course, not every person who diagnoses themselves is truly gluten intolerant. It’s difficult to rule out the placebo effect. It does seem that people with celiac disease or wheat allergies aren’t the only ones who react poorly to gluten. Studies of NCGS have found that these patients share some symptoms of celiac disease and even wheat allergy. What they don’t have is the small intestinal damage visible in celiac patients. If left untreated, celiac disease can lead to fertility problems. Since people with NCGS share some celiac symptoms, could those with untreated NCGS also experience decreased fertility?
Could Non-Celiac Gluten Sensitivity Cause Infertility?
Research is seriously lacking in this area. Untreated (and possibly undiagnosed) celiac disease and inflammatory bowel disease (which includes ulcerative colitis and Crohn’s disease) can cause infertility and pregnancy loss. For that matter, even those being treated for inflammatory bowel disease can experience infertility. Infertility isn’t only caused by disease or malfunction in the reproductive system. The body works as a whole, and when one thing goes wrong, it can impact other systems. Non-celiac gluten sensitivity may one day be added to the list of gastrointestinal disorders associated with decreased fertility. An interesting case study on this topic was reported by the Institute of Health & Society University of Worcester, United Kingdom. The study tells the story of a couple trying to conceive unsuccessfully for four years. The woman was in her late thirties, had a history of IBS (something many people with NCGS present with), asthma, and previous miscarriages. She had relatives with celiac disease and diabetes, but she herself did not have these conditions. Overall, her health looked good. Her weight and hormone profile were normal, she was ovulating, and she tested negative for sexually transmitted diseases. But she couldn’t get pregnant. Her partner’s health also looked good overall, except for suffering from IBS symptoms as well. Semen analysis did reveal poor sperm morphology (sperm shape). Doctors recommended IVF with ICSI to overcome the poor morphology. Despite getting good quality embryos, the couple did not conceive. They then decided to try a gluten-free diet. The woman’s intestinal discomfort didn’t improve on the gluten-free diet, but the man’s did. In fact, the man’s semen quality also improved enough for them to try IVF without ICSI. While waiting to start the next treatment, the couple conceived naturally. Sadly, the woman miscarried 10 weeks later. Finally, after a year on a gluten-free diet — after six years of trying to conceive, many failed IVF cycles, and multiple miscarriages — the couple was able to conceive with IVF. The pregnancy was complicated, and the baby was born prematurely at 30 weeks. The gluten-free diet did seem to improve the male partner’s fertility in a measurable way, bringing his sperm morphology (sperm shape) numbers to normal. While reproductive immunology is controversial and research is ongoing, treatment of these fertility issues has helped couples conceive who could not find success previously. Could gluten play a role?
Natural Killer Cells, Gluten, and Infertility
One area of reproductive immunology involves natural killer cells, or NK cells. They sound like a bad thing to have but actually, NK cells are an important part of the immune system. They are a type of white blood cell that destroys potential cancerous cells and virus-infected cells. Problems begin when there are too many or when they start attacking healthy cells. Having a high percentage of NK cells is suspected of being a possible cause of recurrent miscarriage and failed embryo implantation during IVF. Reproductive immunologists also look at how lethal the NK cells are. In this case, more lethal is not good. How does this relate to gluten? A study of NK cells in the lab and in mice found that exposure to gliadin (part of the gluten protein) increased NK cell presence, toxicity, and activity. There’s currently no research on how this works in the human body.
ANA, Infertility, and Gluten
Another area of reproductive immunology relates to the topic of anti-nuclear antibodies, or ANA. The presence of ANA cells indicates that an autoimmune disorder may be present, causing your body to attack itself. ANA levels are tested when an autoimmune disorder like lupus or rheumatoid arthritis is suspected. However, otherwise healthy people sometimes test positive for ANA levels, although doctors are not sure of the reason. The presence of ANA cells is suspected of causing problems with embryo implantation during IVF treatment. How does this relate to gluten? A 2015 study conducted in Italy looked at people with celiac disease, inflammatory bowel disease (IBS), and non-celiac wheat sensitivity. Those with celiac disease and non-celiac wheat sensitivity were more likely to test positive for ANA than those with just IBS. More specifically, the study found that a positive ANA test occurred in:
46% of those with non-celiac wheat sensitivity24% of those with celiac disease2% of those with IBS
No specific studies have looked at the effect gluten may have on pregnancy success in women diagnosed with endometriosis. There is research on endometrial pain and gluten, however, including a case study of a woman with endometriosis and undiagnosed celiac disease.
Does Gluten Cause More Pelvic Pain?
A study in Italy looked at 207 women suffering from severe endometriosis-related pelvic pain. All of the women were put on a gluten-free diet for one year. After the year, they were asked to report back on their pain levels. One hundred fifty-six patients — or 75% — reported statistically significant improvements of their painful symptoms. About 25% didn’t report any improvements, and none reported increased pain. The women also reported improvements in other areas of life, including general health perception, physical functioning, vitality, and mental health. Could dropping gluten also improve pregnancy success in women with endometriosis? That’s unknown at this time.
Endometriosis and Undiagnosed Celiac Disease
One study of 469 Italian women found a higher rate (although not statistically significant) of undiagnosed celiac disease in those who also had endometriosis. This points to a possible connection between the two disorders, and may indicate one role that gluten could play in infertility. These diets are often low in gluten because many gluten-containing products are high in carbs or have a high glycemic index. They are not truly gluten-free, however. No studies have looked at the potential connection between PCOS and gluten. However, researchers have focused on a possible connection between gluten and diabetes. PCOS is a known risk factor for diabetes, specifically insulin resistance. In fact, the diabetes drug metformin is considered a treatment for PCOS-related infertility. The possible connection between gluten and diabetes may give us a hint of how gluten might impact those with PCOS.
Diabetes and Gluten
Research has shown that a link between gluten and diabetes does appear to exist, as people with celiac disease are more likely to have type 1 diabetes (and other autoimmune disorders.) An interesting study in mice has shown that a gluten-free diet during pregnancy alleviated the signs of type 1 diabetes and celiac disease in the offspring. In addition, a large Danish study in 2018 showed that as the amount of gluten consumed by pregnant women increased, so did their children’s risk of developing type 1 diabetes. Clearly, more research is needed in this area. Currently there are no studies on how this may affect fertility or PCOS. We need more studies on the subject. One day, there may be more evidence connecting gluten intolerance to specific causes of infertility. However, you don’t want to get pregnant one day. You want to get pregnant now. As always, talk to your doctor first. But if they give it their OK, give a gluten-free diet a trial period of at least one month and see what results you get. As long as you eat a variety of nutritious foods while eliminating gluten, a gluten-free diet can be very healthy. As the researchers of one study pointed out, when you compare the cost and potential adverse effects of fertility treatment to the cost and adverse effects of going gluten-free, it could be a good option for some couples, especially those who have gastrointestinal symptoms and/or have experienced failed fertility treatments.
