Discoveries and Data: Specific Conditions



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-7483573 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-7483573 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-7483573 Latinas had the lowest reduction (10%) while Whites had the highest reduction (46%).


bullet-7483573 Most prenatally diagnosed cases during this period were identified by amniocentesis; about 10% were detected by chorionic villus sampling (CVS).
bullet-7483573 88% of prenatally diagnosed cases were terminated.
bullet-7483573 76% of continued pregnancies were liveborn; 24% spontaneously miscarried or ended in fetal death.


arrow_left-9479242 Main Down syndrome page