TRANSABDOMINAL CHORIONIC VILLUS SAMPLING IN THE 2ND AND 3RD TRIMESTERS OF PREGNANCY - CHROMOSOME QUALITY, REPORTING TIME, AND FETOMATERNAL BLEEDING

Transabdominal chorionic villus sampling (TA-CVS) was performed in 210 pregnancies from 13 to 38 weeks using a double-needle technique. The sampling success was comparable to first-trimester TA-CVS and the diag nostic success rate was 98.2 per cent for the short-term technique and 99.3 per cent for cultured villi. Two fetuses could not be karyotyped . We found the chromosome quality to be similar to that in the first t rimester, comparing the number of G-bands and other chromosome attribu tes. There were no unintended losses in a group (n = 142) with no sono graphic abnormality, except for one death in utero at 38 weeks, 20 wee ks after sampling. Chromosomal aberrations were seen in 19 per cent of cases with abnormal sonograms (n = 58). One case of a discordant kary otype was found (false-negative prediction of Down's syndrome by the s hort-term preparation). There were no cases of fetal demise due to fet o-maternal bleeding. It is suggested that double-needle TA-CVS in adva nced pregnancies combines the advantages of rapid karyotyping of chrom osomes of good quality and low risk for the fetus, and seems to be eas ier to practise and is probably safer than cordocentesis.