He worries that if Down syndrome cases decline enough in the U.S. funding to study the congenital condition will dry up. There's also worry that more people will deny themselves what some call the "gift" of raising children with Down syndrome.
Nina Fuller of Newburgh, Ind., knew nothing about parenting a child with Down syndrome when she received her diagnosis.
"I presumed she would not be able to communicate, to read, to interact with the rest of our family or with the world around her," she told ABCNews.com. "I was afraid that she would intrude on the lives of her three brothers, and that our family would be home-bound and our lives as we had planned would be thrown into turmoil."
Those fears never materialized. The Fullers went on to adopt another daughter with Down syndrome, Hope.
Without knowing what it's like to raise a child with Down syndrome, many women will make their decisions based on misinformation -- and myths -- about the disorder, say advocates.
The genetic diagnosis often comes as a shock, and many people assume that raising a child with Down syndrome will be fraught with heartbreak.
Melanie McLaughlin, a Boston mother who decided to raise her child after a Down syndrome diagnosis, said she worried about how the child would affect her siblings and the marriage, and who would look after her when she and her husband died.
But according to a study by Skotko, whose sister has Down syndrome, most siblings are patient and compassionate. As for the marriage, some couples do experience stress in raising a disabled child, but many grow closer.
"I am concerned about mothers making that informed decision," he said. "Are they making it on facts and up-to-date information? Research suggests not, and that mothers get inaccurate, incomplete and sometimes offensive information."
Like Skotko, CDC experts worry about ensuring care for the complex health problems associated with Down syndrome, such as congenital heart defects, as children progress through adulthood.
The CDC study drew on birth defect registries in Arkansas, Georgia, California, Colorado, Iowa, North Carolina, New York, Oklahoma, Texas, and Utah. The regions covered 29 percent of all births in 2002.
Of the estimated 5.5 million live births, 6,580 were diagnosed with Down syndrome. The highest rates were in Utah and the lowest were in Arkansas.
According to the report, crude rates of Down syndrome at birth were slightly higher among boys and Hispanics.
For more information, go to the National Down Syndrome Society.