What is a designer baby?

A designer baby is one whose genetic make-up has been selected in order to eradicate a particular defect, or to ensure that a particular gene is present. Advanced reproductive technologies allow parents and doctors to screenembryos for genetic disorders and select healthy embryos.

In-vitro fertilisation or IVF
The fear is that in the future we may be able to use genetic technologies to modify embryos and choose desirable or cosmetic characteristics. Designer babies is a term used by journalists to describe this frightening scenario. It is not a term used by scientists.

Advanced reproductive techniques involve using InVitro Fertilisation or IVFto fertilise eggs with sperm in 'test-tubes' outside the mother's body in a laboratory. These techniques allow doctors and parents to reduce the chance that a child will be born with a genetic disorder. At the moment it is only legally possible to carry out two types of advanced reproductive technologies on humans. The first involves choosing the type of sperm that will fertilise an egg: this is used to determine the sex and the genes of the baby. The second technique screens embryos for a genetic disease: only selected embryos are implanted back into the mother's womb. This is called Pre-implantation Genetic Diagnosis (PGD).

Though parents may not be able to screen their future babies for genes that confer intelligence, hair color or athletic aptitude just yet, a company, 23andme, recently applied for a patent on such tests. Soon it may be possible to screen the entire genome of a fetus, or to select a child based on its odds of long-term diseases such as Alzheimer's or diabetes.