The pamphlet, written for physicians and other health professionals who counsel parents, explain five factors which put women at high risk of giving birth to a child with Down's Syndrome and three antenatal diagnostic techniques. Five factors identified as indicating high risk are advanced maternal age (over 40 years old), a previous child with Down's Syndrome, chromosomal translocation in mother or father, parental mosaicism, and Down's Syndrome in the mother. Briefly examined are the uses of amniocentesis, amniography, and ultrasonography as antenatal diagnostic techniques, the risks of amniocentesis, the benefits of proper diagnosis, and what parents can expect if they have a child with Down's Syndrome. (GW)