Bioethical issues associated with the generation and storage of human embryos

Javier del Río-Riego, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Manuel Duarte-Pérez, Department of Gynecology and Obstetrics, Hospital Universitario La Paz, Madrid, Spain
Ana García-Belda, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Tamara Rodríguez-Pérez, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Lydia Pascual-García, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Cristina Pizarro-Sánchez, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Carolina González-Varea, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Marta Segovia-Amaro, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Rebeca Gómez-Casaseca, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
Silvia Iniesta-Pérez, Department of Gynecology and Obstetrics, Hospital Universitario La Paz, Madrid, Spain
Alicia Hernández-Gutiérrez, Department of Gynecology and Obstetrics, Hospital Universitario La Paz, Madrid, Spain
Antonio Buño-Soto, Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain

Background: Infertility affects 15-20% of couples globally, leading to increased use of assisted reproductive technologies. Innovations in in vitro fertilization and intracytoplasmic sperm injection, especially embryo vitrification, have enhanced embryo survival and optimized transfer timing. However, the proliferation of cryopreserved embryos raises unresolved legal and ethical issues. Objectives: This review explores the legal classifications and ethical implications surrounding cryopreserved embryos, highlighting cross-jurisdictional perspectives and the need for integrated policy frameworks. Methods: A qualitative analysis of legal texts, bioethical literature, and regulatory approaches in Spain and other jurisdictions was conducted to identify key challenges related to embryo status, storage, and disposition. Results: Legal definitions of embryo status differ internationally, with Spanish law emphasizing the developmental stage and human dignity. Ethical concerns include surplus embryo management, preimplantation genetic testing, donation, and research use. The accumulation of cryopreserved embryos intensifies debates around parental rights, abandonment, and longterm storage. Conclusions: Comprehensive frameworks are needed to align reproductive advances with societal values and ethical responsibility. Refining policies on embryo disposition and reproductive autonomy is essential in addressing the complex implications of modern ART.

Keywords: Ethics. Embryology. Assisted reproduction. Cryopreservation.