Quiz Entry - updated: 2026.10.22
What is the difference between preimplantation genetic diagnosis (PGD) and prenatal diagnosis?
PGD genetically tests cells of an embryo created by IVF in the lab, before it is transferred into the uterus; prenatal diagnosis examines an unborn child during pregnancy to detect health problems and developmental disorders early.
| Preimplantation genetic diagnosis (PGD, PID) | Prenatal diagnosis (Pränataldiagnostik) | |
|---|---|---|
| When | before pregnancy begins | during pregnancy |
| On what | cells of an embryo created by artificial fertilisation, in vitro | the foetus in the womb |
| Typical aim | detect hereditary diseases before transfer | detect problematic health conditions and developmental disorders early |
| Ethical core | selection among several embryos | decisions about an existing pregnancy, possibly abortion |
The timing explains why the two raise different questions: PGD implies choosing which embryo is transferred (and discarding others), which critics link to "designer babies" and to judgements about the value of lives with disabilities. Prenatal diagnosis instead confronts parents with decisions about an ongoing pregnancy.
Go deeper:
Wikipedia: Preimplantation genetic diagnosis — procedure, uses and ethical debate.- Wikipedia: Prenatal testing — screening and diagnostic tests during pregnancy.