What is PGD?
By using PGD to study an embryo’s genes, a scientist can find out which embryo has the best chance of growing into a healthy baby.
The couple use in vitro fertilisation (IVF) to produce about ten embryos. Some will contain the disease genes and others will not. Scientists test and select the healthiest embryos from these.
The scientist takes each two or three-day old embryo and removes a cell to test for the particular genes in question. The scientist now knows which embryos contain a copy of the disease genes and which don’t. The doctor will implant the healthiest embryos into the mother.
Some people wrongly think that parents can choose any characteristic or gene for their baby. In reality, parents can only select for genes that they have themselves. Genes cannot be added to an embryo.