Chorionic villi sampling with an echogenic catheter: experiences of the first 500 cases

Using a newly developed CVS catheter with enhanced echogenicity we performed CVS in 501 consecutive cases. The abortion rate of 4.3% prior to 28 weeks of gestation in this series is within the background rate of controls matched for maternal age. The loss rate was clearly correlated to the number of insertions, time of sampling and sampling success. CVS is safest between 9 and 11 weeks of pregnancy. We recommend to restrict the number of insertions to a maximum of 3. The rate of failed samplings was 4, reflecting a low "aggressiveness in seeking a sample". Complete follow-up of 259 consecutive cases gave no indication of an increased rate of congenital anomalies following CVS in early pregnancy. In our study we also performed cervical swabs, pregnancy hormone testing, maternal serum AFP determination prior to and after CVS as well as maternal AFP screening at 16 weeks of pregnancy together with a detailed sonographic examination. We conclude that CVS can be considered now a safe and reliable diagnostic procedure, but requires further detailed documentation and close follow-up in controlled trials.