During the period 1987 through mid-1993, 118 490 chromosome analyses from amniocytes were performed at the Integrated Genetics Laboratories in Santa Fe, New Mexico (formerly Vivigen Laboratories). This report summarizes the data for all specimens submitted because of anomalies seen during ultrasound examination; this includes 44 different categories of anomalies. There were 3177 cases referred because of at least one structural abnormality; 494 (15.5 per cent) of the cases had an abnormal karyotype. Our cytogenetic findings are summarized for the different types of anomalies and the corresponding empirical risks are given for abnormal cytogenetic results.