Background: Chromosomal structural rearrangements can lead to fertility prob-lems and recurrent miscarriages. The intricate interplay of genetics during hu-man development can lead to subtle anomalies that may affect reproduction.
Case Presentation: A 33-year-old woman sought fertility treatment after expe-riencing six miscarriages. Products of conception from the final pregnancy loss had been karyotyped, revealing a Robertsonian translocation (RT), involving chromosome 14. Fertility investigations showed low anti-Mullerian hormone (AMH) levels but otherwise normal female characteristics with normal sperm parameters of her husband were observed and both partners having a normal karyotype. Two embryos were transferred in an IVF cycle but neither resulted in a successful pregnancy. Subsequently, preimplantation genetic testing for an-euploidy (PGT-A) was applied to trophectoderm biopsy specimens from 4 em-bryos, which revealed abnormalities involving chromosome 14. Sperm aneu-ploidy testing failed to detect any increase in the incidence of aneuploidy af-fecting chromosome 14. Further embryos genetic testing indicated that all iden-tified chromosome 14 abnormalities in the embryos had a maternal (oocyte) origin.
Conclusion: This case underscores challenges in diagnosing and managing germline mosaicism in fertility. A maternal 14;14 Robertsonian translocation, undetected in the patient's blood but impacting oocytes, likely explains recur-rent miscarriage and observed embryo aneuploidies. Genetic mosaicism in re-productive medicine highlights the necessity for advanced testing and personal-ized treatments. Data integration from various genetic analyses could enhance managing treatment expectations and improving fertility experiences.