PRENATAL GENETIC SERVICES FOR DOWNS-SYNDROME - ACCESS AND PROVISION IN 1990-1991

Objective To examine access to and provision of prenatal genetic servi ces relating to Down's syndrome. Design Retrospective review of obstet ric casenotes. Sample Pregnancies involving Down's syndrome in England and Wales in 1990-1991 in women aged 38 or over. Information was obta ined in 430 cases from a questionnaire completed by the obstetric team who were asked to provide details based only on documentation in the antenatal casenotes. The outcome of pregnancy was a termination in 268 (62%) cases, a liveborn child with Down's syndrome in 144 (34%), a st illbirth in 9 (2%), a miscarriage in 8 (2%) and in one case was not kn own. Results Overall, prenatal diagnosis was not offered in 7% pregnan cies (95% CI: 4.4-9.2%) with late booking given as the main reason. Of women offered prenatal diagnosis, 76% accepted (95% CI: 72.3-80.6%). Counselling was documented before prenatal diagnosis in 89% of cases ( 95% CI: 86.0-92.3%) and after the procedure, to discuss the results, i n 73% (95% CI: 67.5-77.7%). In 10% of pregnancies terminated for Down' s syndrome, fetal products were not sent to the laboratory. There was no report of a normal fetus having been terminated as a consequence of incorrect prenatal diagnosis. However, in 10% (95% CI: 5.9 to 14.0%) of cases examined in the laboratory, the diagnosis of Down's syndrome could not be confirmed. Details of prenatal diagnosis were not provide d in five cases where a child with Down's syndrome was born. Of the re maining 139 livebirths, prenatal diagnosis was not offered in 27 (19%) cases, offered and declined in 92 (66%) and accepted in 20 (14%). In two cases a normal fetal karyotype was reported following prenatal dia gnosis. Conclusions The study has demonstrated that in 1990-1991: 1. T here were certain shortcomings in the documentation of antenatal care; 2. Late booking was the main factor precluding the offer of prenatal diagnosis to women aged 38 or over, and 3. The rate of confirmation of Down's syndrome in terminated fetuses was incomplete.