Couples trying to conceive may want to add a gluten-free diet to their regimen. Research shows a clear link between celiac disease (gluten intolerance) and infertility in both women and men.

Infertility affects about 10 percent of couples wanting to have children, or more than 6 million Americans. Several studies have shown the prevalence of celiac disease is higher in women with unexplained infertility. Also, women with celiac disease are three times more likely to miscarry and four times more likely to experience complications in pregnancy.

Gluten’s effect on the reproductive system extends beyond fertility. In a 2011 Russian study, women with celiac disease generally began menstruating a year or more later than their peers, and suffered significantly more menstrual irregularities and amenorrhea (lack of menstruation).

Knowing whether gluten intolerance is a pregnancy risk can be difficult as symptoms aren’t always obvious. Studies have shown women with undiagnosed celiac disease often do not have digestive complaints, the symptom most associated with celiac. This is consistent with findings in the general population: the majority of those with celiac disease do not, in fact, suffer from digestive problems.

Hashimoto’s hypothyroidism and infertility

This is a double whammy for those with Hashimoto’s hypothyroidism, as studies also link gluten intolerance and celiac disease with the autoimmune thyroid disease.

Some research also shows a link between Hashimoto’s hypothyroidism and infertility. For instance, elevated TPO antibodies, a marker for Hashimoto’s, are associated with poor treatment response in infertile women who also suffer from polycystic ovarian syndrome (PCOS). Women with hypothyroidism have been shown to have a poor response rate to in vitro fertilization, and Hashimoto’s is associated with more pregnancy complications in one study.

An important strategy to tame the autoimmune response that attacks the thyroid gland and causes hypothyroid symptoms is to adopt a gluten-free diet. This may also reduce the risk of infertility, as well.

Gluten, hypothyroidism also affect male fertility

Women aren’t the only ones whose reproduction is affected by gluten intolerance. Male fertility is also at risk. Newer research shows that 20 percent of married men with undiagnosed celiac disease have infertile marriages. Semen analysis has shown problems with both the structure of sperm and its motility. Another study showed men with undiagnosed celiac disease tend to have hormonal imbalances that may lead to infertility. There is good news, however. Sperm function and hormone balance were both shown to improve on a gluten-free diet.

Also, men with hypothyroidism are shown to have sperm abnormalities and erectile dysfunction.

Studies look at narrow segment of gluten-intolerant population

These studies, while illuminating, look at celiac disease only, which accounts for a small minority of people with a gluten intolerance. Celiac disease is an autoimmune reaction to gluten. “Gluten intolerance” is a broader category that includes people whose health is compromised by gluten, although their reaction may not be autoimmune. If studies were expanded to include the full range of those who have an immune reaction to gluten, the rates of infertility and birth complications due to gluten intolerance could be found to be quite a bit higher.