ABSTRACT
The development of techniques for diagnosing genetic disorders in utero was a major advance in medical genetics and has so altered the outlook for families at risk of having affected children that it has become one of the main options open to those receiving genetic counselling, especially where there is a high risk of a serious and untreatable disorder. Treatment may be clear-cut and satisfactory in some disorders that might otherwise be considered for prenatal diagnosis. The acceptability of termination of pregnancy to a couple must be determined before any prenatal procedures are contemplated. The final point to be emphasized here is that the risk of the disorder occurring in a particular pregnancy must be estimated accurately before prenatal diagnosis is considered; in other words, the consideration of prenatal diagnosis must be an integral part of genetic counselling. The rare, but high-risk, group with translocation Down syndrome comprises only 5% of all cases of Down syndrome.
