[Reliability of the advice given at genetic counselling: follow-up study].

A follow up investigation was carried out in order to estimate the reliability of the advice given at our genetic counselling clinic. Data were collected mainly by questionnaires sent by mail in November, 1983 to 556 clients counselled during the period January, 1976 - December, 1982. The outcome of 444 pregnancies for 361 clients was revealed. They were divided into three groups according to the risks estimated and suggested by the counsellors; below 2% (Group I), 2 - 9% (Group II) and 10% or more (Group III). The following results were obtained. The incidence of those who had not become pregnant following the day of counselling was higher in Groups II and III than in Group I. The rate of spontaneous abortion was higher in Group III than in Groups I and II. The incidence of pregnancies with children affected by birth defects for which the risks were estimated was 1.5% in Group I, 6.5% in Group II and 26.5% in Group III. Six to nine percent of babies of all groups suffered from other diseases such as intrauterine fetal death, congenital anomalies, developmental abnormalities or severe infectious diseases. The recurrence rate for regular trisomic Down's syndrome was 1.8%. These results suggested that the risk estimates and advice were quite reliable and helpful.