Risk Evaluation in a Small Series of Transabdominal Chorionic Villus Sampling

Abstract

Previous reports have suggested that the fetal loss rate with transcervical chorionic villus sampling was high in the initial 100–300 procedures performed. In a consecutive series of 155 patients with first-trimester transabdominal chorionic villus sampling (CVS), we observed a total fetal loss rate of 8.4%, and a loss rate not attributable to induced abortion or cytogenetic abnormality of 3.2%. Our results demonstrate that transabdominal CVS in the first trimester of pregnancy is a safe method of prenatal diagnosis.

First trimester prenatal diagnosis: earlier is not necessarily better.

“…This difference cannot be expected to improve substantially since CVS uses cells from the placenta rather than directly utilizing fetal cells for analysis as does amniocentesis. About 3.5 per cent of CVS procedures need to be repeated or followed up by amniocentesis because of failure to obtain adequate material for analysis, matemal cell contamination, and/or mosaicisma condition where chromosomal abnormalities only appear in some of the cells (5,6,7,8).…”

“…Although CVS appears to pose little risk to the woman, there is a 3.2 per cent procedure-related fetal loss; with amniocentesis this rate is less than 1 per cent (4,5,6,7,9). Fetal loss appears to be highest with transcervical CVS (10,11).…”

“…In other words, if the difference in risk between CVS and amniocentesis is 2 per cent, an estimate which is probably on the low side, there will be as many as 66 normal fetuses lost for every 100 abnormalities detected ( 11). Initially it was conjectured that the procedure-related loss would drop as operators became more proficient in performing the procedure (6). However, this has not proved to be the case (9).…”