FIRST-TRIMESTER CHROMOSOME BY LAVAGE OF THE UTERINE CAVITY

Fetal karyotyping of trophoblast cells obtained by lavage of the uteri ne cavity was evaluated on 86 first-tremester irrigation fluid samples . Villus fragments were observed in 72 fluid samples indicating an 83 . 7 per cent sampling success rate. The amount of villi in these sampl es ranged from 1 to 32 mg. In most cases, villus fragments showed dege neration of the external syncytiotrophoblast layer and absence of bloo d vessels. In the first phase of this study (15 samples): a high degre e of maternal cell contamination was observed after long-term cultures . In the following phase (71 samples), this obstacle was overcome by t he appliction of a semi-direct method. Chromosome preparations were se t up after 24 h incubation of villus fragments and QFQ-banded metaphas e spreads were scored for chromosome number and sex. Sixty samples sho wed the presence of villus fragments and the fetal karyotype was estab lished in 40. Male and female chromosome complements were observed in 16 and 24 cases, respectively. In four cases, an abnormal fetal karyot ype was diagnosed. These included trisomy of chromosomes 13, 15, and 1 6, and one mosaic with trisomy 12. Our results indicate that first-tri mester fetal karyotyping might be feasible by a semi-direct method usi ng chorionic villus fragments obtained at intrauterine lavage.