Genetic analysis of products of conception. Should we abandon classic karyotyping methodology?

OBJECTIVE: To compare the results obtained by the classic and molecular methodology in the analysis of products of conception, the advantages and disadvantages of each method. METHODS: Retrospective non-randomized analysis of results obtained from product of conception samples submitted to genetic evaluation, from 2012 to 2017. The evaluations were performed using cytogenetics and/or chromosomal microarray analysis or arrays. RESULTS: Forty samples were analyzed using classic cytogenetics, of which 10% showed no cell growth, 50% had normal results and 40% had abnormalities. Of the 41 cases sent for array analysis it was not possible to obtain results in 7.3%, 39.5% were normal and 60.5% had abnormalities. There was no statistical difference among the results (p=0.89). Most abnormal results were seen till 9 weeks’ gestation. The later abnormal miscarriage was seen at 28 weeks’ gestation, with karyotype 46,XX,del(15)(q26.2-qter). The results are corroborated by the international literature. CONCLUSION: Classic cytogenetics and array techniques showed comparable results on the type of alteration observed. Array analysis is preferable to cell culture in delayed abortions, while cytogenetics is more able to show polyploidies. Both have the same growth failure rates when product of conception tissue is not properly collected.