Transabdominal chorion villus biopsy: 100 consecutive cases

A series of 100 transabdominal chorionic villus biopsies were carried out for maternal age (34 patients), fetal sexing (15), previous aneuploidy (21), biochemical analysis (5), gene-probe analysis (17), and oligohydramnios or fetal anomaly (6). 18 patients were over 14 weeks pregnant at the time of sampling. Tissue samples were obtained from 98 patients, including one set of twins. All 99 tissue samples proved adequate for laboratory diagnosis. Chromosome mosaicism was encountered in 4 cases (among direct preparation karyotypes in 1 case, between direct and cultured cells in 2 cases, and between chorion cells [both direct and cultured] and the fetus in 1 case). No patient miscarried but 1 had a stillbirth and 1, who had undergone transcervical biopsy before referral to our hospital, started to bleed before termination of pregnancy because of a diagnosis of cystic fibrosis. These data suggest that the transabdominal method of chorion biopsy will fulfil its theoretical and early promise.