Population screening for aneuploidy using maternal age and ultrasound.

The coexistence of an epidemiological register and a multidisciplinary centre for prenatal diagnosis promoted us to report data collected during six years (1990-1995) in Isère county on prenatally detected chromosomal aberrations. During the whole study period prenatal diagnosis strategy towards chromosome aberrations was based solely on maternal age and ultrasound examination. Results showed a respective contribution of one-third/two-thirds for the two detection modes (maternal age/ultrasound signs).

Application of fluorescence in situ hybridization to the identification of different marker chromosomes.

Chromosome studies performed on lymphocyte culture of a baby with specific dysmorphism and congenital anomalies suggestive of trisomy 21 revealed a mosaicism: 46,XY,rea(21q21q) [25]/47,XY,rea(21q21q),+mar1[25]. The karyotype of the mother is normal, but the father's karyotype presents an supernumerary chromosome greater and different from the marker of his son: 47,XY,+mar2 (100%). The identification of the two marker chromosomes by standard cytogenetic techniques followed by molecular techniques is essential for the identification of the origin of these two chromosomes.

[Choriocentesis: comparison of the effectiveness of a new choriocentesis needle and a transcervical biopsy forceps].

71 samples taken by the transabdominal route were compared with 71 samples taken by forceps through the cervix. A fine (1 mm) transabdominal choriocentesis needle with a thin wall (0.1 mm), a short bevel, and a lateral hole was made to bring together simplicity, effectiveness and safety; success was obtained in 95% of the cases (39/41) of our last 41 samples on the first attempt.

[Role of karyotype in studying male infertility].

The karyotype of 443 infertile males has been studied (infertility of unknown etiology). The sample has been divided in 3 groups according to the data of their spermogram: Gr 1--101 males with a normal spermogramm (selected through the sterility of their couple). Gr 2--185 infertile males with oligospermy (less than 20 millions spermatozoal/ml).