search for information spacer
search birth defects
search environmental factors
search geographic areas
birth defects the solution is research discoveries and data serving the public visitor type
home page
discoveries and data center
all birth defects
specific conditions
exposures and risk factors
geographic data

take our survey

Look up in our Glossary

chorionic villus sampling (CVS)
pregnancy termination
prenatal diagnosis

reference informationReferences

down syndrome: impact of prenatal diagnosis

An in-depth study of 1989-1991 births calculated the impact of prenatal diagnosis and subsequent medically indicated pregnancy termination of affected pregnancies on the observed Down syndrome rate.

bullet Down syndrome was noted in 1.1 per 1000 livebirths; adjusting for medically indicated pregnancy terminations, the rate is 1.5 per 1000 livebirths.
bullet There was a 26% reduction in livebirths with Down syndrome due to prenatal diagnosis and medically indicated pregnancy termination. A 49% reduction was seen for mothers over age 35, with a 7% reduction for births to mothers under 35.
bullet Latinas had the lowest reduction (10%) while Whites had the highest reduction (46%).


bullet Most prenatally diagnosed cases during this period were identified by amniocentesis; about 10% were detected by chorionic villus sampling (CVS).
bullet 88% of prenatally diagnosed cases were terminated.
bullet 76% of continued pregnancies were liveborn; 24% spontaneously miscarried or ended in fetal death.

reference information

Main Down syndrome page

contact information