Frequency of Chromosomal Abnormalities in Products of Conception

Abstract

Purpose To describe the frequencies of chromosomal abnormalities found in abortion material, and to observe its correlation to maternal age. Methods A retrospective study was conducted based on data obtained from the databank of a medical genetics laboratory in Belo Horizonte, MG, Brazil. A total of 884 results from products of conception analysis were included, 204 of which were analyzed by cytogenetics, and 680 by molecular biology based on quantitative fluorescence polymerase chain reaction (QF-PCR). The frequency of individual chromosomal aberrations and the relationship between the presence of anomalies and maternal age were also evaluated. Results The conventional cytogenetics technique was able to detect 52% of normal and 48% of abnormal results in the analyzed material. Quantitative fluorescence polymerase chain reaction revealed 60% of normal and 40% of abnormal results from the samples evaluated by this method. The presence of trisomy 15 was detected only by cytogenetics, as it was not included in the QF-PCR routine investigation in the laboratory. A significant increase in abnormal results was observed among women aged 35 years or older compared with younger women (p ¼ 0.02). Conclusion Chromosomal aberrations are still a major cause of spontaneous abortion, and the conventional cytogenetics technique is efficient for miscarriage material analysis, but molecular methods such as QF-PCR are adequate complementary strategies to detect the major chromosomal anomalies, leading to technical reports with reliable results.

Chromosomal abnormalities in recurrent miscarriages by conventional karyotyping analysis

“…55 The other was conducted in 884 products of conception, 204 of which were analyzed by cytogenetics and 680 by molecular biology based on QF-PCR. 56 Despite using different techniques, the abnormal results were similar (40% by QF-PCR and 48% by cytogenetics). 56 A recent study, using only conven-tional CA, with 457 products of conception showed that 382 cases were sucessfully karyotyped while 75 cases of cell culture failed (culture failure rate: 16.42%).…”

“…56 Despite using different techniques, the abnormal results were similar (40% by QF-PCR and 48% by cytogenetics). 56 A recent study, using only conven-tional CA, with 457 products of conception showed that 382 cases were sucessfully karyotyped while 75 cases of cell culture failed (culture failure rate: 16.42%). Cytogenetic abnormalities were detected in 127 of the 382 cases (33.24%).…”

“…11,12 The CA of products of conception presents at least two main challenges, cell culture failure and excess of normal woman karyotypes related to maternal cell contamination. Although the CA of abortive material is highly recommended, alternative complementary techniques for CA such as Fluorescence in situ Hybridization / FISH, 52,53 Multiplex Ligationdependent Probe Amplification / MLPA, 54 Quantitative fluorescent polymerase chain reaction / QF-PCR 55,56 and array Comparative Genomic Hybridization / CGH 57 have been used for genetic testing on miscarriage samples. These techniques do not require cell culture and have been proposed to optimize the genetic results in unsuccessful karyotype.…”

“…55 Other studies using cytogenetics found lower frequencies (33.24% and 48%) of chromosomal abnormalities. 56,59 Two studies published in 2014 and 2017 employed CA and QF-PCR. 55,56 The first applied CA on 534 miscarriages, 73% (390/534) of them was successful.…”

“…56,59 Two studies published in 2014 and 2017 employed CA and QF-PCR. 55,56 The first applied CA on 534 miscarriages, 73% (390/534) of them was successful. One hundred and forty-four miscarriages (27%, 144/534) did not grow in culture.…”