Impact of genetic counseling and prenatal diagnosis for Down syndrome and neural tube defects.

In two parallel studies the impact of genetic counseling and prenatal diagnosis upon family planning decisions was evaluated for parents of a child with Down syndrome and for parents of a child with neural tube defect. One hundred and nineteen parents of a child with standard trisomy 21 volunteered to participate in study I; 94 parents who had a neural tube defect child took part in study II. Each study included three groups of parents: one group received genetic counseling, another group had already an amniocentesis performed and a third group of parents had neither received genetic counseling nor had they an amniocentesis performed. Data collection took place by means of interviews by a social nurse at the parents' home. An exhaustive questionnaire was used to guide the interview and to assess the total impact of the birth of the affected child as completely as possible. Some years later additional follow-up information was gathered by sending a questionnaire to all families. In both studies a significantly better recall of the relevant risk figures was found in the counseled group as compared with the group of parents who did not receive genetic counseling. The relationship between the recalled risk and its subjective interpretation was very complex. The information given during the counseling session(s) influenced more than half of the parents of a child with Down syndrome, to decide in favour of further pregnancies. In the group of parents having a child with neural tube defect the information received at the genetic counseling session(s) even had a more important effect: 80 percent decided to plan another pregnancy. Results of both studies clearly indicate that for more than half of the families the availability of prenatal diagnosis was of crucial importance in the decision to plan future pregnancies.