Trends in cytogenetic prenatal diagnosis in a reference hospital in Izmir/Turkey: a comparative study for four years.

The aim of the study was to investigate the major changes in the indications, culture success and abnormality rate for conventional cytogenetic prenatal diagnosis on amniotic fluid samples between the period of January 1998 and December 2001 in Izmir. The cytogenetic laboratory provides a prenatal service to obstetrics-gynecology departments of different hospitals in Izmir. A limited number of patients (6-8 per week) is randomly accepted for prenatal cytogenetic study. Over the 4 years period 1190 prenatal cytogenetic tests were performed in our center. The most common indication was advanced maternal age for each year. However its rate has increased significantly within the years (35.68% in 1998, 61.38% in 2001), while the rate of both triple test and ultrasound scanning indications decreased. Culture success rates have improved (97.97% in 1998, 99.74% in 2001). Comparing the first two years to the last two years the rate of abnormal cytogenetic results decreased significantly (3.83% in 1998-99, 2.48% in 2000-01). The major reason for this decrease is probably related to the changes in indications throughout the years.