Evidence check: tTG IgA in the context of Fruchtbarkeit

tTG IgA (tissue transglutaminase IgA) is the primary serological marker for celiac disease. Untreated celiac disease can impair fertility through malabsorption, chronic inflammation, and autoimmunity—affecting both women (menstrual irregularities, recurrent miscarriage) and men (reduced sperm quality). Evidence comes from observational studies and clinical guidelines, not randomized controlled trials, so the evidence level is human-moderate. A positive tTG IgA test alone is not a fertility test but indicates possible celiac disease, which should be confirmed by duodenal biopsy. In IgA deficiency, IgG-based tests are needed. Some guidelines recommend testing in unexplained infertility, but universal screening is not standard. Importantly, the test is specific, but not every positive result leads to fertility issues. A gluten-free diet can improve fertility in confirmed celiac disease. The utility of direct-to-consumer tests (e.g., MyBody-X) for tTG IgA is limited because they often lack medical interpretation. Overall, the test is useful but should be part of a comprehensive fertility workup.