Incidence and Spectrum of Chromosome Abnormalities in Miscarriage Samples: A Retrospective Study of 330 Cases

Embryonic chromosome abnormalities are the most important causes of early spontaneous abortions. The aim of this study was to evaluate the spectrum and the frequencies of chromosomal anomalies in spontaneous miscarriages and to correlate these with maternal and gestational age. A retrospective study was conducted based on data obtained from a single medical genetics laboratory that collects cases from Western Romania. Long-term cultures of chorionic villus samples were established for karyotype analysis by GTG banding. Additionally, we performed QF-PCR to detect aneuploidies for chromosomes 13, 18, 21, X, and Y. In total, chorionic villi samples of 330 miscarriages (from August 2007 to November 2018) were analyzed. Results were obtained for 90.6% (299/330) of the cases. The remaining 9.4% (31/330) were excluded from evaluation due to inconclusive results. An abnormal karyotype was found in 156 cases (47.27%), while in 143 cases (43.33%) a normal karyotype was present. Of the abnormal cases, 88 (56.4%) had trisomies, 25 (16.0%) presented polyploidies, 25 (16.0%) had monosomy X, and 19 (11.5%) chromosome rearrangements. QF-PCR analysis identified aneuploidy in 2 out of 8 samples (25%). Cytogenetic investigations of spontaneous abortions provide valid data as to the cause of the abortion. This information may also be helpful for genetic counseling and considering future pregnancies.