Original ResearchUterine Glands Agenesia in the Mare

•Over 300 uterine equine endometrial specimens underwent histological evaluation as a part of breeding soundness examination.•Two cases of endometrial glands agenesia were diagnosed.•Adenogenesis disturbances lead to infertility. Uterine biopsy is the procedure of choice to diagnose this developmental disorder.

All mammalian uteri contain endometrial glands that synthesize and secrete a substance termed histotroph, which is essential for early pregnancy nutrition. Because of that function, endometrial glands play a crucial role as regulators of survival and development of conceptus. In all mammalian females as well as in woman, endometrial glands undergo extensive hyperplasia and hypertrophy during pregnancy as a response to increasing demands of the developing conceptus for uterine histotroph. The process of endometrial glands development is called adenogenesis. Inhibition of the development of these glands through gene mutation or epigenetic strategies results in infertility. Two cases of total intrauterine glands developmental agenesis are presented, which were diagnosed on the base of histopathological examination of endometrial biopsy specimens. Despite the fact that endometrial glands agenesis in mare is a rare condition, it is worth while to emphasize that the endometrial biopsy is currently the best diagnostic tool to recognize the above developmental disturbance. Clinicians should be aware that the mare with normal reproductive organs during macroscopic clinical investigation can present with uterine glands agenesis.