[Select embryos: preimplantation genetic diagnosis]

Area of Science:

• Assisted human reproduction
• Embryo genetics
• Bioethics

Context:

• Assisted reproductive technologies offer alternatives to eugenic abortion and enable older women to conceive.
• Preimplantation genetic diagnosis (PGD) and in vitro embryo screening (PSC) are presented as methods to avoid chromosomal defects.
• These techniques raise ethical questions regarding human experimentation and the selection of embryos.

Purpose:

• To critically evaluate the ethical implications and scientific rigor of preimplantation genetic diagnosis and screening.
• To address the potential for "positive eugenics" through embryo selection based on desired traits.
• To highlight the lack of validation and potential harms associated with current PGD/PSC methodologies.

Summary:

• PGD and PSC are presented as reproductive tools but are critiqued for their ethical shortcomings and lack of scientific validation.
• The techniques are associated with direct human experimentation without therapeutic intent and raise concerns about embryo selection and disposal.
• Concerns include the absence of animal model validation, leading to diagnostic errors (false positives/negatives), and the unknown effects of embryo biopsy.

Impact:

• Challenges the ethical permissibility of PGD/PSC due to potential for discrimination and lack of scientific certainty.
• Underscores the need for rigorous scientific validation and ethical oversight in assisted reproductive technologies.
• Raises awareness about the potential for unintended consequences and harm to human embryos in early developmental stages.