Infertile couples were recruited in Tabriz, Iran, between October 2006 and September 2007. After a complete evaluation of their endocrine status, one hundred couples with unexplained infertility were chosen for this study. Two hundred couples with at least one child and no reproductive problems served as controls. Thirteen infertile subjects - 5 men and 8 women - had elevated levels of tissue transglutaminase antibodies, compared to eleven controls - 4 men and 7 women. Fourteen infertile subjects and eleven controls were found to be IgA deficient; of these, three of each had elevated tissue transglutaminase IgG. Based on this serology, the researchers note that the likelihood of celiac disease in infertile patients is 2.39 times higher than in controls; the frequency of celiac disease is 8% in infertile patients, compared to 3.5% in controls.
Only five infertile subjects and four controls with elevated tissue transglutaminase antibodies agreed to have duodenal mucosal biopsies; the remainder had no gastrointestinal complaints or other symptoms, so they opted out of the endoscopy. According to the biopsy, celiac disease was indicated in three cases of unexplained infertility compared to one case in the control group.
Previous studies have demonstrated that men with celiac disease have an increased incidence of hypogonadism, sexual dysfunction, and poor semen quality. Women with celiac disease can have major menstrual problems. Systemic diseases like celiac can exert subtle effects on the reproductive system in both genders. A gluten free diet can alleviate infertility if it is caused by nutritional imbalances due to celiac disease, such as malabsorption of zinc, selenium, iron, and folate.
This Iranian study, like previous studies in Finland, Italy, Israel, and the US, thus seems to come down on the side of celiac disease, as measured by serological markers, being more significantly frequent among couples with unexplained infertility than in controls.