Prenatal and Preimplantation Genetic Testing: Technologies, Advances, and Ethical Considerations

The chapter reviews the rapid evolution of prenatal and preimplantation genetic testing, from conventional cytogenetics to non-invasive prenatal testing based on cell-free foetal DNA and the application of whole-genome approaches in preimplantation genetic testing for aneuploidies and monogenic disorders. It evaluates the sensitivity, specificity, and clinical utility of current platforms, and discusses the implications of expanded carrier screening programmes. Ethical dimensions — including reproductive autonomy, incidental findings, and the limits of genetic prediction — are addressed with nuance and depth.