[Transabdominal chorionic biopsy: indications and timing of the procedure].

The article reports on the introduction of transabdominal chorionic biopsy in the Gynaecological Hospital of Ludwigshafen in cooperation with the Department of Human Genetics at the University of Heidelberg. After completion of a pilot study 15 diagnostic transabdominal chorionic biopsies were performed between the 15th and 23rd pregnancy week. Sampling was successful in all cases; the median estimated weight of the biopsied samples was 35 mg. Cytogenic, biochemical and molecular-genetic examinations were conducted. No complications were seen except for one subserous haematoma. Indications and time of performance are discussed. The transabdominal chorionic biopsy is easier to conduct in the 2nd trimenon than during the first, and can therefore be considered to be a favorable "entry" into the technique. Shifting the biopsy to an earlier date, namely, into the first trimenon, can be aimed at as the familiarity with the technique increases. The obvious advantages of transabdominal removal of villi compared with the transcervical method lead us to expect that in course of the time the transcervical method will be replaced by the transabdominal one. No indication for invasive prenatal diagnosis should be implied without previous detailed genetic counselling.