Pro & Con: Should preconceptional and prenatal cystic fibrosis carrier screening be a routine part of obstetrical care? (Opinion).

YES

All physicians who do Y E S obstetrics should offer screening to people with a family history of cystic fibrosis, reproductive partners of people who have the disease, and couples in whom one or both members are white and who are planning a pregnancy or seeking prenatal care.

Those recommendations were issued in September 2001 by the American College of Obstetricians and Gynecologists and the American College of Medical Genetics (ACMG), in jointly issued guidelines for cystic fibrosis (CF) carrier screening.

The guidelines were intended to specify what's best for patients--not consider whether physicians have time to do this, whether insurance will pay for it, or whether CF carrier screening will be controversial relative to the abortion issue.

In 1989, investigators cloned the gene for CF and identified its most common mutation. At that time, CF screening had about a 70% sensitivity, meaning that about half of the couples who would have a child with CF would learn that they are at high risk.

During the 1990s, investigators discovered more than 900 different mutations of the CF gene. Meanwhile, pilot trials of CF carrier screening showed two things: Patients generally were not interested in getting screened until they were already pregnant. And when some couples were offered the screening, they decided to have it. If one or both parents were found to be a CF carrier, they would often make decisions to continue or terminate the pregnancy based on information obtained by prenatal diagnosis.

The latter observation led to a recommendation in 1997 by a National Institutes of Health consensus panel: There are enough people who want CF carrier screening that we need to make it available to them.