Defining the role of fluorescence in situ hybridization on uncultured amniocytes for prenatal diagnosis of aneuploidies

Fluorescence in situ hybridization (FISH) analysis of uncultured cells from the amniotic sac may be a more rapid method of detecting fetuses with abnormal numbers of chromosomes than conventional methods. Researchers compared results of FISH and of conventional karyotyping in 315 pregnant women undergoing amniocentesis for suspected fetal abnormality as detected by ultrasound, blood tests, or based on maternal age. FISH provided useful, accurate information for 80.6% of pregnancies (254). FISH was quicker than conventional karyotyping, taking 2.8 days versus 8.3 days to complete. FISH was most accurate for pregnancies 24 weeks or earlier.