[Status of prenatal diagnosis using direct interventions on the fetus].

Prenatal diagnosis has developed into a large flourishing multidisciplinary branch of medicine. At present prenatal diagnosis is world-wide possible in the second trimester of pregnancy by analysis of both amniotic fluid obtained by amniocentesis or amniotic cell cultures. Ultrasound plays a central role in prenatal diagnosis, and has revolutionized obstetric practice. Without dealing with all aspects of prenatal diagnosis we have discussed the following invasive procedures, which give the prenatal diagnosis its forward thrust: fetal blood sampling including intravascular transfusion, fetal skin-, liver- and muscle biopsy, chorion biopsy, selective birth in twin pregnancies, and fetal therapy including fetal surgery. In utero surgery is in its earliest stages. Such simple procedures as decompression of the hydronephrotic kidney in obstructive uropathy, of the fetal lungs in pleural effusions caused by chylothorax, or of the hydrocephalic ventricle may be useful, but the possible success rate for such efforts remains still uncertain. The possibilities of first-trimester prenatal diagnosis especially by DNA-technology or direct chromosomal and biochemical analysis has stimulated the development of a multiplicity of methods for taking chorion biopsies. Compared with second trimester amniocentesis, the introduction of prenatal diagnosis by chorionic villi sampling would reduce the psychic trauma for patients waiting on results and allow earlier and safer termination of pregnancy.