• Coeliac disease
• infertility

In a recent paper in Gut, describing a Swedish population-based cohort, Zugna et al found that women with coeliac disease had normal fertility, but their fertility had decreased in the 2 years preceding the diagnosis of coeliac disease.1

This study provides important answers to fertility problems in patients with coeliac disease by analysing a nationwide database. The results, however, must be interpreted with caution. This paper may be considered confusing because the role of coeliac disease as one of the causes of infertility has been underestimated taking into account population studies in general. Infertility, spontaneous abortion and delayed puberty represent subclinical coeliac disease presentations and, in our opinion, could be resolved on a gluten-free diet (GFD). In fact, there is a significant difference in patients with coeliac disease when comparing the period before initiating a GFD and after commencing the diet. The malabsorption of vitamins and nutrients, together with the activation of the immune system, required to active coeliac disease, significantly improves after the recovery of intestinal histological lesions. Comparing women with treated coeliac disease and reference women, no difference can be found in terms of malabsorption, or as far as fertility is concerned. Nevertheless, decreased fertility was detected over the 2 years preceding diagnosis, underlying the crucial role of a GFD in active coeliac disease.

In our experience we report the case of four women (aged 28–39 years) who attended our hospital for infertility (lasting 2–12 years) and who were diagnosed with coeliac disease. Astonishingly, all of them became pregnant after only 2–9 months of a GFD. In particular, a 39-year-old woman had spent 11 years trying to become pregnant, including 4 years wasted undergoing in vitro fertilisation treatment. She was anti-endomysium and anti-transglutaminase antibody positive and carried the HLA DQ2 heterodimer. On a GFD the patient improved her quality of life and normalised her serology after 9 months. After 2 years she delivered a baby.

Fertility is probably restored by histological, clinical and pathological remission, which causes the normal fertility reported by Zugna et al in women treated for coeliac disease.1 The immediate effect of a GFD in our patients may suggest a major role of selective nutrient defects, such as folate, zinc, antioxidants or micronutrients essential for the metabolism of carrier or receptor proteins for sex hormones.2 In addition, thrombosis due to hyperhomocysteinaemia, which is caused by malabsorption of vitamin B₁₂ is frequently involved in infertility.3

In conclusion, we strongly suggest the necessity of coeliac disease screening in barren women and the importance of including coeliac disease-related autoantibodies in the diagnostic flow-chart of couples with fertility troubles. In fact, the high prevalence of coeliac disease,4 and the occurrence of oligo-asymptomatic forms, which frequently contribute to the delay of the diagnosis, require screening programmes in this group as the only way to reach a correct diagnosis. The grieving process among both men and women after unsuccessful attempts to become pregnant is well known. Efforts should be made to achieve an early and specific diagnosis of the causes of sub-fertility, in order to deal with the physiological reduction of reproductive potential due to ageing.