[Amniocentesis and trophoblastic biopsy. Comparison of results]

The purpose of this study was to compare the changes observed over 4 years in the prenatal diagnosis of genetic diseases and congenital malformations by amniocentesis (AC) and trophoblast biopsy (TB). Between January 1, 1986 and December 31, 1989, 2,591 requests were recorded in a wide geographical area. A general increase in the number of cases per year was observed (414 in 1986, 870 in 1989). The number of requests for TB has distinctly raised in absolute values (14 cases in 1986, 250 in 1989), as well as in relative values compared with AC (3.5% in 1986 40% in 1989). The number of foetal abnormalities detected has tended to diminish with AC (3%) and to increase with TB (4%). At the time of sampling, there was no significant difference in the mothers' mean age between AC (33.9 years) and TB (36.4 years).