Fetal genetic diagnosis by chorionic villus sampling.

Abstract

(CVS) is a first trimester method of obtaining genetic information for prenatal diagnosis of fetal ahnormalities in women whose fetus is at high risk. Historically, attempts at first trimester fetal diagnosis were made almost simultaneously with the early development of midtrimester amniocentesis primarily by the Scandinavians in the late 1960s. Mohr ’ first proposed the transva‘ginal-transcervital biopsy of fetal tissue. Together with Hahneman”,” he developed a 4-mm diameter hysteroscope introduced through the internal OS into the uterus for direct endoscopic vision of the developing placenta and biopsy of the chorion. All of a cohort of 95 patients underwent terminations, but 29 of these patients who had the procedure done without anesthesia were then observed for 8 days.” Only 96% of biopsies were successful. Points of failure included puncture or biopsy of the amnintic membrane and bleeding that obscured vision. Approximately 47% of the procedures contained chorion villi. A total of 42% of the 28 procedures performed in outpatients were said to be “inconsistent with the continuation of the pregnancy.” The authors5 felt that the “dimensions, unwieldy structure and complexities (of the hysteroscope) were probably responsible for many of the complications.” and 1 lth gestational weeks were most suitable for obtaining placental biopsies. However, by this time the problems of amniocentesis had largely been solved and the rapid acceptance of this method reduced the effort on first trimester trials with their high fetal risk and complex instrumentation.