Related Experiment Videos
Down's syndrome: current screening techniques
1Department of Obstetrics and Gynecology, George Washington University Medical Center, Washington, DC.
Antenatal screening for Down's syndrome traditionally relied upon performing amniocentesis for karyotype on pregnant women aged 35 years and older. This method detects approximately 20% of all Down's syndrome pregnancies, with a false-positive rate of 4.3%. By incorporating maternal serum alpha-fetoprotein values as an additional screening parameter to maternal age, 28% of all Down's syndrome pregnancies may be diagnosed, with a 35% reduction in false-positive results. Other screening parameters such as maternal serum unconjugated estriol and human chorionic gonadotropin may eventually make it possible to detect more than 65% of pregnancies with chromosomally abnormal fetuses, without compromise in false-positive rates.
Antenatal screening for Down's syndrome traditionally relied upon performing amniocentesis for karyotype on pregnant women aged 35 years and older. This method detects approximately 20% of all Down's syndrome pregnancies, with a false-positive rate of 4.3%. By incorporating maternal serum alpha-fetoprotein values as an additional screening parameter to maternal age, 28% of all Down's syndrome pregnancies may be diagnosed, with a 35% reduction in false-positive results. Other screening parameters such as maternal serum unconjugated estriol and human chorionic gonadotropin may eventually make it possible to detect more than 65% of pregnancies with chromosomally abnormal fetuses, without compromise in false-positive rates.