The Right to Try: Patient-Driven Mosaic Embryo Transfer in a Restrictive Policy Setting

Objective: To highlight how a university-affiliated fertility clinic balanced its policy against high-level mosaic embryo transfers with ethical and legal obligations to respect patient autonomy. Design: Single case report. Materials and Methods: A 43-year-old woman underwent publicly funded IVF and developed three blastocysts. PGT using next-generation sequencing identified two aneuploid embryos and one high-level mosaic embryo with trisomy 2 and partial trisomy 20pter-p11.23. Despite the clinic’s policy against transferring highly mosaic embryos, the couple insisted on proceeding. In response, the clinic initiated a six-month multidisciplinary process, including advanced genetic counselling, formal ethics board review, legal consultation with a lawyer specializing in assisted reproduction case law, and the development of a customized informed consent form detailing risks and uncertainties. Results: The patient underwent ovulatory frozen embryo transfer (FET) after completing the consent process. She conceived, with normal noninvasive prenatal testing (NIPT) and first-trimester ultrasound. Amniocentesis at 18 weeks confirmed a chromosomally normal female fetus. The pregnancy proceeded without complications, resulting in the birth of a healthy female infant who is developing normally at 3 months old. Conclusions: This case illustrates the nuanced balance between institutional policies and patient autonomy in reproductive medicine. With thorough counselling and multidisciplinary support, fertility clinics can ethically honour patient-directed choices—even when they conflict with protocols. As mosaic embryo transfer becomes more prevalent, particularly for patients with limited embryo availability, such collaborative frameworks are crucial. This case emphasizes the need for personalized reproductive care, robust informed consent, and continued research to refine embryo selection strategies to reduce the current 5-10% rate of false positives for highly mosaic embryos. Support: In-kind contribution from ONE Fertility.