Doctors Screen Birth Defects

Several Medical School professors are seeking to introduce a genetic screening process to New England Medical Center that may detect fatal birth defects during prenatal care.

The screening process tests for neural tube defects, which affect the development of the brain and spinal cord. It has been used extensively in Great Britain and on a small scale in the United States, where it is awaiting regulatory approval.

Dr. Lewis Holmes, associate professor of Pediatrics, said last week that he is raising funds to start a program that would give any pregnant woman receiving care at Peter Bent Brigham and Women's Hospital in Boston the opportunity to undergo the screening.

The program is "past the point of research," and ready for use, Holmes said.

The development of a new technique that can determine whether observed AFP levels are attributable to neural tube defects or to other possible causes has improved the effectiveness of the genetic screening process, Holmes said.

While his current efforts are aimed only at Brigham and Women's, the New England Regional Genetics Group, a regional branch of the federal Department of Health and Human Services, is seeking to coordinate a mass screening program for all of New England.

Co-chaired by Dr. Allan Crocker, associate professor of Pediatrics and head of the developmental disabilities unit at Children's Hospital, and Dr. Richard Erbe, associate professor of Pediatries, the group plans a network of laboratories and testing centers, that would include, Massachusetts General Hospital, Brigham and Women's.

Erbe said that a large-scale regional effort is necessary to provide a significant sample size from which to evaluate the effectiveness of the screening process. He added that a two-year trial run would be helpful.

AFP testing "has been going on in the U.S. in private programs for quite some time," Holmes said, but he and Erbe agreed the demand for prenatal diagnosis is definitely on the rise.

Erbe attributed this increase to several factors. For example, the trend of women delaying having children until after they have established a career has led to an increased probability of birth defects. But a Food and Drug Administration (FDA) review of the manufacture of the immunological reagents required by the procedure has delayed its use on a large-scale basis. The agency is expected to set down regulations on the use of these chemicals this summer.

Because the laboratories cooperating with the Erbe and Holmes effort antedate the regulation, they can continue AFP testing without waiting for FDA approval. These research centers include the Eunice Kennedy Shriver Center in Waltham, where Dr. Aubrey Millunsky, assistant professor of Pediatrics, has been directing AFP testing since 1973, and the Foundation for Blood Research in Scar-borough, Maine.

Holmes said he hopes to begin the program at Brigham and Women's as soon as he can raise the money for starting costs. Erbe added that the genetics group hopes to begin its regional operation within a year.

While administration of the test itself is not costly, both doctors stressed that educating the public about the test could prove problematic.

"Getting the information across stands between the present time and any widespread testing," Erbe said. Many people have never heard of the defects caused by neural tube defects, Holmes said. Furthermore, because the defects are often fatal, there are few visible examples in society of their effects. he emphasizes that a strong commitment to education and counseling is essential.

Although Holmes is optimistic that the AFP tests will prove effective, he is uncertain what action the FDA will take. The regulations that would enable the screening process to become widely available. He noted the opposition to the process expressed by anti-abortion groups at the FDA hearings last month might influence the agency's decision and prevent the screening process from becoming widely available.

Erbe is cautious about launching a permanent large-scale program before the screening process has been assessed more thoroughly. "I don't think you can turn loose something like this without having undertaken assessment," he said.

But he expressed confidence that the FDA would approve the proposed regulations. Then, he said, widespread screening would begin slowly.