Down testing advised in all pregnancies

Down testing advised in all pregnancies
Copyright © 2006, Chicago Tribune and The Associated Press
Published December 31, 2006

WASHINGTON -- The American College of Obstetricians and Gynecologists this week begins recommending that every pregnant woman, regardless of age, be offered a choice of tests for Down syndrome.

Until now, testing for the common birth defect hinged on whether the woman was older or younger than 35.

The main reason for the change: Tests far less invasive than the long-used amniocentesis are widely available, including some that can tell in the first trimester the risk of a fetus having Down syndrome or other chromosomal defects.

The change promises to decrease unnecessary amnios while also detecting Down syndrome in moms who otherwise would have gone unchecked.

The new guideline is published in January's issue of the journal Obstetrics & Gynecology.

About 1 in 800 babies has Down syndrome, a condition where having an extra chromosome causes mental retardation, a characteristic broad, flat face and small head and, often, serious heart defects.

Age 35 was always a somewhat arbitrary threshold for urging mothers-to-be to seek testing. The older women are, the higher their risk of having a baby with Down syndrome. But it's a gradual increase in risk--from 1 in 1,200 at age 25 to about 1 in 300 at age 35.

"It's clear there's no magic jump at 35," said Dr. James Goldberg of San Francisco Perinatal Associates, a member of the American College of Obstetricians and Gynecologists committee that developed the guideline. "We've done away with age 35 because the screening tests have gotten much better."

The original age-35 trigger was chosen years ago when doctors had less information about the risk of Down syndrome and the only choice for prenatal detection was an amnio, using a needle to draw fluid from the amniotic sac, he said. Amnios occasionally cause miscarriage.