en 39157282 <p>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.<br /> 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.<br /> Conclusion: This case underscores challenges in diagnosing and managing germline mosaicism in fertility. A maternal 14;14 Robertsonian translocation, undetected in the patient&#39;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.</p> In vitro fertilization, Miscarriage, Mosaicism 66 72 https://www.jri.ir/article/140211 https://www.jri.ir/documents/fullpaper/en/140211.pdf XavierGonzalezEmbryology Department, Aria Fertility, London, UKxavier@ariafertility.co.uk41896FranciscaMoraEmbryology Department, Aria Fertility, London, UK122630FalakArshadReproductive Genetics Department, Juno Genetics, Oxford, UK122631YipingZhangReproductive Genetics Department, Juno Genetics, Oxford, UK122632DhrutiBabariyaReproductive Genetics Department, Juno Genetics, Oxford, UK41898DaganWellsReproductive Genetics Department, Juno Genetics, Oxford, UK41901AmandaTozerClinical Department, Aria Fertility, London, UK122634