Cytogenetic study of spontaneous abortions by transabdominal villus sampling and direct analysis of villi

Abstract

We report our experience in a cytogenetic study of 93 spontaneous abortions. Specimens were obtained by transabdominal chorionic villus sampling (TACVS) in women requesting prenatal diagnosis by chorionic villus sampling (CVS) but in whom an arrested pregnancy had been diagnosed during the ultrasound examination. Our success rate, i.e. the percentage of cases where we obtained results, was 91. 4 per cent, and the rate of abnormalities-mostly aneuploidies and polyploidies-was 62.3 per cent. In normal cases, masculine:feminine ratio was 1:1. These results confirm those obtained by other groups earlier this decade and allow us to conclude that, for the cytogenetic study of spontaneous abortions, CVS is a better approach than the culture of the products of conception after evacuation, because the success rate is higher and because it provides certainty that the specimens obtained are of fetal origin.

Chromosomal anomalies in first‐trimester miscarriages

“…The karyotype 47,XXY seems to be associated with an advanced maternal age. The mean maternal age of the present study was in the same interval as in other comparable studies where the age is stated (2, 9, 11, 12). Hence, our data could suggest that, as for monosomy X, a majority of the 47,XXY conceptions do not survive to term.…”

“…women within a defined geographic area diagnosed with miscarriage, without selection for age or a prior desire to perform prenatal diagnosis. This is in contrast to some previous reports, where the total study group or parts of the group consisted of women requesting prenatal diagnosis (2, 8, 9). A higher mean maternal age and a larger proportion of chromosomally abnormal cases in those studies might be a reflection of this selection.…”

“…There was no excess of female fetuses among the cases, indicating that maternal cell contamination is of minor importance using direct preparation of chorionic villi, compared to cultures established from products of conception. Others also corroborate this finding (e.g., 9).…”

“…This pattern was also found in several other studies, although trisomy for chromosome 2 is not generally noted as frequently (7, 8, 11–14). The trisomy 2 was revealed in seven of our cases, and has been detected in less than 15 miscarriages before (2, 8, 9, 11–14). We found trisomies for all chromosomes, except for chromosomes 5, 7, and 19.…”

Application of a new molecular technique for the genetic evaluation of products of conception

“…Up to 80% to 90% of the chromosomal defects in POC are due to numerical abnormalities, with monosomy X, triploidy and autosomal trisomy being the most common . Our karyotyping experience in 2900 abortive tissues (1995–2011) is as follows: in approximately one‐third of the cases, there was cell growth failure ( n = 985; 33.9%); in the remaining cases ( n = 1915) with a karyotype result, half were abnormal ( n = 951; 49.7%), and two‐thirds of the abnormal cases had an aneuploidy that would be detectable by KaryoLite™ BoBs™ ( n = 695; 73.1%) (Table ).…”