Prenatal Diagnosis of Chromosomal Abnormalities through Amniocentesis

The incidence of major chromosome abnormalities in newborns is about 0.7 percent and increases with maternal age. Amniocentesis is the most common invasive prenatal procedure for the detection of fetal chromosomal abnormalities. Amniocentesis is a relatively safe procedure and fetal loss related to amniocentesis is about 0.5%. An advanced maternal age is the most common reason for using amniocentesis. The use of amniocentesis because of abnormal fetal ultrasound findings has increased recently. Fluorescence in situ hybridization (FISH) is currently a powerful tool in the area of prenatal cytogenetics. The number of amniocentesis procedures in Japan is about ten thousand per year and it is generally recognized to be a great benefit for pregnant women who have a risk of fetal chromosomal abnormalities.