Urine test to check for Down syndrome

December 7, 1999
Web posted at: 3:42 p.m. EST (2042 GMT)

WASHINGTON (Reuters) -- Researchers at Yale University said Monday they would try out a new urine test on pregnant women to check if their fetuses have Down syndrome.

They hope to find that the hyperglycosylated hCG test can be done on a urine sample, without the need to draw blood, and that it will be more accurate than current screening tests.

Currently, blood tests are used to screen pregnant women for the probability that their child has Down syndrome, and a second test, amniocentesis, gives a more definitive diagnosis.

Down syndrome is the leading genetic cause of mental retardation and occurs in one of every 700 live births.

Children with the syndrome have one extra chromosome and are not only mentally retarded but also often have physical defects.

Dr. Maurice Mahoney and Dr. Ray Bahado-Singh of Yale said they would enroll 10,000 women in their study. They will be given ultrasound, blood screening and the new urine screening tests to compare accuracy.

The urine test was developed at Yale, but Teterboro, New Jersey-based Quest Diagnostics Inc. holds half of the patent rights.

Bahado-Singh said the blood test missed about 40 percent of Down syndrome in fetuses. Early trials with the urine test suggest it is 80 percent accurate.