Abortion risk in chorionic villus sampling. Evaluation in elective termination of pregnancy.

100 patients were examined to evaluate the risk of abortion of chorionic villus sampling. In the 8th-10th week of pregnancy a catheter with a mandrin was introduced into the chorion frondosum under ultrasound guidance. The mandrin was then removed and trophoblast tissue obtained by aspiration. The patients agreed to postpone elective termination of pregnancy for 2 weeks. Another ultrasound was performed before suction curettage. With increasing experience, the abortion rate dropped to 4%, whereas the rate of successful biopsies and analyses rose to more than 90%. Based on these results, chorionic villi sampling was made available at the 1st Department of Obstetrics and Gynecology, University of Vienna, as an alternative method to amniocentesis. Out of 38 biopsies, 25 karyotypes were normal, two biopsies revealed pathological results (trisomy 21, 22), 11 samples showed no results (insufficient tissue or no mitoses). One patient had a spontaneous abortion (trisomy 22) and one an abortion due to infection. Chorionic villus sampling could replace amniocentesis because chromosomal anomalies may be detected already in the 1st trimester of pregnancy.