Completed follow-up of 1,000 consecutive transcervical chorionic villus samplings performed by a single operator

Completed follow-up data on 1,000 patients undergoing transcervical chorionic villus sampling (CVS) performed by a single operator at the Royal Hospital for Women is presented. Prior to the introduction of CVS, approximately 750 amniocenteses were performed annually in this unit. Over the past 5 years the total number of patients having CVS or amniocentesis has increased by 1/3 and almost 1/2 of procedures are now done by CVS. We have persisted with the transcervical route believing that once the learning curve is past, this route compares favourably with the transabdominal method in loss rate and perinatal outcome. We feel the transcervical approach is better tolerated by our patients and that less procedural difficulties are encountered. With increasing operator experience the total fetal loss rate to 20 weeks' gestation in our series declined to 2.1% and late complications were no more frequent than expected. In 98.4% of patients, sufficient villi were obtained for analysis. Culture failure was extremely uncommon, occurring only twice in our series. In 1.5% of patients, a follow-up amniocentesis was required, which compares favourably with other published series. It appears that many units abandoned the transcervical route before loss rates were stabilized. In units where transcervical CVS is still performed the transabdominal route is also utilized. The reverse is not true. The authors feel that both procedures have a role in modern antenatal diagnosis.