Down's syndrome can be detected by a simple, inexpensive blood test for pregnant women, UCSD genetic researchers have confirmed in a study to be published this month.
The study, to appear in the American Journal of Obstetrics and Gynecology, measured levels of human chorionic gonadotropin (hCG)--a protein made by the placenta--in pregnant women across the country.
Although researchers have known since 1987 that high levels of the protein are associated with Down's syndrome, the UCSD study is the first to conduct clinical tests on pregnant women on a large scale, said Mark Bogart, assistant research geneticist at the UC San Diego School of Medicine and the principal investigator of the study.
Previous studies had tested for levels of hCG in pregnancies where the outcome had been known, Bogart said.
The screening, combined with the age of the woman and testing the levels of another protein, can accurately predict 65% of Down's syndrome pregnancies, according to the study.