Recent trends in the prevalence of Down syndrome in north-eastern France.

Examination of data from our regional registry of congenital anomalies indicated that 217 children with Down syndrome (DS) were registered (liveborn, stillborn or termination of pregnancy) to mothers living in the Strasbourg area from 1980 to 1992 inclusive. This represents a period prevalence of 1.25 per 1000 total births. From 1980 to 1987, 93 children with DS were registered (prevalence of 0.79 per 1000) whereas from 1988 to 1992, 124 trisomic 21 were identified (prevalence of 1.81 per 1000). In our country since 1980, prenatal diagnosis is offered, free of charge, to all women being 38 years old or more. The percentage of women in whom prenatal diagnosis was performed was "en plateau" since 1986, around 60 per cent. No screening program based on detection of markers in maternal serum (AFP, hCG, U3) is available in our region. A changing pattern of risk in relation to maternal age was identified. In the general population, women under 35 years gave births to 91.7 per cent of all children in 1986 and to 81.1 per cent of all children in 1990. From 1980 to 1987 34.7 per cent of the children with DS were registered in mothers older than 35 years of age, from 1988 to 1992 this percentage was 46.3. From 1982 to 1987, 33 DS were born alive from mothers over 35 years whereas from 1988 to 1992, 25 livebirths DS were born from mothers over 35 years although interruption of DS pregnancies was more frequent in women older than 35 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)