CYSTIC-FIBROSIS NEWBORN SCREENING - IMPACT ON REPRODUCTIVE-BEHAVIOR AND IMPLICATIONS FOR GENETIC-COUNSELING

Objective. To evaluate the impact of newborn screening for cystic fibr osis (CF) on the reproductive knowledge and behavior of CF families an d to determine if heterozygote detection with the immunoreactive tryps inogen (IRT) method in conjunction with DNA analysis (IRT/DNA) influen ces knowledge and attitudes about reproduction in false-positive famil ies. Methods. The Wisconsin CF Neonatal Screening Project investigated 650 340 infants from 1985 to 1994 in a comprehensive randomized contr olled trial to study both benefits and risks of newborn screening and to determine if early diagnosis would improve the prognosis of childre n with CF. Assessments of reproductive knowledge, attitudes, and behav iors of 135 families of children diagnosed as having CF in both the ea rly treatment group and control groups were made 3 months after diagno sis using a questionnaire which was completed by 100 families. The sam e questionnaire was administered 1 year later to evaluate retention of information. It was completed by 71 families. A follow-up assessment tool was also administered in 1994 and responses obtained from 73 fami lies. Knowledge, attitudes, and behavior among false-positive families were also assessed at the time of the sweat test in 206 families who experienced IRT screening and 109 families tested with the IRT/DNA met hod. Follow-up assessments were completed 1 year later in 106 IRT fami lies and 63 IRT/DNA families. Results. In families with a CF child, 95 % initially understood that there was al in 4 risk in subsequent pregn ancies, and there was good retention of this information 1 year later. At the 1994 assessment, 52% of families had not yet conceived more ch ildren, but 74% of these already had children. In the couples in whom CF was diagnosed in the first child, 70% (95% confidence interval = 54 % to 85%) conceived more children. There were 43 subsequent pregnancie s in 31 families. Prenatal diagnosis was used by 26% of the families ( 8/31) for 21% of the pregnancies (9/43). There were 3 pregnancies with CF detected, all of which were carried to term. In the false-positive groups, >95% of families initially understood that their child defini tely did not have CF. There was no difference between false-positive I RT and IRT/ DNA groups, and the information was retained at 1 year. Fo llow-up assessment 1 year after negative sweat tests revealed that 7% of the IRT and 10% of the IRT/DNA families still thought about the res ults often or constantly. When asked whether the experience of screeni ng affected feelings about having more children, an affirmative respon se was obtained in 4% of IRT families but in 17% of IRT/DNA families. One year later, more than half of the false-positive IRT/DNA families did not understand that they were at increased risk of having a child with CF. Conclusions. We conclude that CF neonatal screening does not have a significant impact on the reproductive behavior of mast familie s and that prenatal diagnosis is not used by the majority of CF famili es. IRT/DNA testing experiences seem to affect attitudes about having more children, and some parents are confused about the implications of the results, even with genetic counseling. However, persistent concer ns about the sweat test result are limited. Questions raised by this s tudy confirm the need for more research regarding the process of genet ic counseling and its impact on reproductive attitudes and behavior in the newborn screening setting.