Prenatal diagnosis of genetic disorders and foetal anomalies has expanded significantly. Hundreds of conditions can be diagnosed through DNA analysis of foetal cells and ultrasound and maternal serum biochemical screening. The purpose of prenatal diagnosis is to rule out the presence in the foetus of a particular medical condition for which the pregnancy is at an increased risk. This information is provided to the individual or couple to assist in the decision-making process regarding the possible options including: carrying the pregnancy to term, preparing for a difficult delivery, preparing for the birth of a child with genetic anomalies and for special newborn care, or terminating the pregnancy. Preimplantation genetic diagnosis (PGD) involves the creation of embryos outside the body and their subsequent biopsy, in order to test for a genetic disorder. The stated advantage of PGD over prenatal diagnosis or testing is that the genetic diagnosis takes place at a much earlier stage. As a pregnancy has not been established, couples or individuals will not have to consider abortion, which is likely to be a much more stressful and difficult decision than the disposal of affected embryos in their earliest stage of development. It is expected that the range of conditions for which PGD is available will expand as the genes implicated are identified. Prenatal genetic testing and preimplantation diagnosis raise a number of ethical and legal issues that will be discussed below following a brief description of PND and PGD techniques
