This European collaborative study addresses the question whether a predictive test result for Huntington's disease (HD) has an effect on subsequent reproduction by comparing carriers and non-carriers of the Huntington mutation. A unique characteristic of this study is that this evaluation is done in persons at reproductive age who had a predictive test after the identification of the Huntington gene and who were counselled in one of the participating centres. Data were collected for 180 carriers and 271 non-carriers who received a predictive test result in the period 1993 ± 1998 in Aberdeen, Athens, Cardiff, Leiden, Leuven, Paris or Rome. The mean age of the total study group was 31.5 years and for about half of the group the follow-up interval was 3 years or more, with a maximum of 7 years. The collaborative study clearly revealed an overall impact of the predictive test result on subsequent reproduction: 14% of the carriers had one or more subsequent pregnancies vs 28% of the non-carriers. In the total carrier group a prenatal test was carried out in about two thirds of the pregnancies and one child was born after preimplantation genetic diagnosis; artificial insemination by donor, egg cell donation or adoption were not reported. A more refined analysis was performed in the subgroup with a follow-up interval of at least 3 years and who reported`family planning' as a motive to apply for predictive testing in the pretest period. The complexity of this motive is discussed. In this subgroup with a desire for children in the pretest period the effect of the predictive test result was more pronounced: 69% of the non-carriers had subsequent pregnancies while only 39% of the carriers who mentioned`family planning' as one of the major reasons to apply for predictive testing had a subsequent pregnancy. Of the carriers with one or more subsequent pregnancies the percentage using prenatal diagnosis was slightly higher than the percentage not using it, although there were clear differences from one centre to another. The latter group's decisions may seem more intriguing but may be partially understood based on stage theories of health behaviour. Last, but not least, whatever option is chosen by a couple at increased risk of transmitting the Huntington mutation, it is of the utmost importance that professionals fully respect this decision and support the couple.

This European study involving seven genetic centres from six countries -Aberdeen, Cardiff (UK), Leiden (Netherlands), Leuven (Belgium), Paris (France), Rome (Italy), Athens (Greece) has gathered information on prenatal testing by direct mutation analysis and exclusion testing for Huntington's disease (HD) from the six European countries during the period 1993 -1998. Data describing the parent belonging to the HD family was collected; this included their sex and age as well as their risk of developing HD. Information about previous pregnancies, the rank of the pregnancy being tested and its outcome was also gathered. In addition the number of previous prenatal tests for HD was recorded. Three hundred and five results were recorded by the participating countries between 1993 and 1998. The largest groups came from the UK (157) and the Netherlands (90). The mean age for the parent from the HD family was 30.8 years. In half of the tests the prospective parent was an asymptomatic gene carrier, 42% remained at risk, and 6% of the prospective parents were already showing clinical features of HD. 65% of tests performed used mutation analysis.

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Objectives: It was the main aim of the present retrospective study carried out in Flanders to evaluate how women with a false-positive triple test result look back on their experience and decision making and how many of them make use of the triple test in subsequent pregnancies. Methods: All 508 women tested in the Centre for Human Genetics in Leuven in 1995 who had a positive triple test result followed by a normal amniocentesis outcome were invited to participate in a mailed questionnaire study with open and multiple choice questions in 1998. The response rate was 68%. Results: The answers to the multiple choice question assessing how they look back on their initial expectations regarding the exact meaning of the triple test revealed that less than one half reported that it concerned the identification of ‘a higher risk of carrying a child with Down syndrome (DS)’. Reporting correct initial expectations was significantly associated with a higher education level. The same holds for indecisiveness regarding pregnancy termination should the amniocentesis have detected a fetus with DS. As expected, a large majority of the women reported a high level of distress or worry after the communication of the positive triple test result. Overall the findings show that retrospectively most women had the feeling that the decision to have amniocentesis was their own decision rather than a professional’s. Of the subgroup with one or more subsequent pregnancies 70% had another triple test. Conclusions: The overall results of this study clearly reveal a need for a systematic approach aimed at better informing and counselling pregnant women about the implications and limitations of the triple test. Notwithstanding the reported high level of distress caused by a positive triple test result, a large majority of the women with subsequent pregnancies had another triple test; they represent a clearly higher percentage than in another recent study.

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