The Down Syndrome Dilemma

Sheila and Peter Hebein learned that their first and only child had Down syndrome on the day he was born, in 1972. "I remember kind of stopping breathing," Sheila recalls. Prenatal testing was rare in those days, and because she was only 30, she was not a candidate. "One of the most challenging things about that day is that you're on a great high because you just had a baby," she says. "Then someone comes in and says, 'Yeah, you had a baby, but ... ,' and how they say that but is critical." The Hebeins, who live in Evanston, Ill., will be forever grateful to their pediatrician, Arthur Dechovitz, for the way he delivered that but. "When Chris was born, parents were being told to institutionalize their children. We never had that kind of experience," Sheila says. "The doctor said, 'Here's your baby. Who do you think he looks like? The most important thing is that you love him and you treat him like you would treat any other baby.'" Hebein, who has served as executive director of the National Association for Down Syndrome since 1979, says, "We never had negative input from the beginning, so I think that got us off to a good start."

Thirty-three years later, fewer women are surprised in the delivery room the way Sheila Hebein was. Screening for Down syndrome became a routine part of U.S. prenatal care around 1990. Typically, women are offered a "triple screen" blood test during the second trimester of pregnancy (see chart). The results are entered into a computer along with the mother's age, and the machine spits out her individual risk of carrying a child with Down. If the risk is high--say more than 1 in 300--she will be offered amniocentesis, a needle-in-the-belly test that allows doctors to conclusively diagnose genetic aberrations, including Down, but carries about a 1-in-300 risk of causing miscarriage. If an extra 21st chromosome is found--the hallmark of Down--the woman or couple face a fateful choice: to terminate a pregnancy that has already reached the second trimester, or prepare to raise a child with Down, which causes mild-to-moderate retardation and often other health problems as well. Doctors estimate that 80% to 90% choose the first path.

For years, doctors have hoped to offer women the opportunity to weigh their options earlier. Last week brought good news on that front. A $15 million study, six years in the making and funded by the National Institute of Child Health and Human Development, found that a method of screening women for Down in the first trimester is an even better indicator of risk than second-trimester screening. The aptly named FASTER study (for first- and second- trimester evaluation of risk), published in the New England Journal of Medicine, determined that if done properly, the first-trimester screening detects 87% of fetuses with Down at 11 weeks gestation, while the second-trimester blood screening detects 81% if four substances are screened and only 69% if the more popular triple-screen test is used. Most accurate of all--with a 96% detection rate--is a "fully integrated" calculation that combines both results.