CHALLENGES FOR CHROMOSOME ANALYSIS IN PREGNANCY LOSS: LESSONS LEARNED FROM 1208 SAMPLE EXPERIENCE

Abstract

Objective: Previous studies have shown that half of the spontaneous abortions were associated with fetal chromosomal abnormalities, however it is not always possible to reveal the reasons of pregnancy loss. The aim of the current study was to investigate the frequency of chromosome abnormalities and culture failure rates of pregnancy loss and compare the results with similar studies in the literature. Material and Methods: The karyotype analysis results of 1208 abortion materials which were obtained from long-term cultures of chorionic villus samples of the patients who were admitted to the Haseki Training and Research Hospital Genetic Diagnosis Center between August 2016 and February 2021, were evaluated retrospectively. Results: No results were obtained due to culture failure in approximately half of the materials. Numerical anomalies were observed in 87% (116) of abnormal karyotypes that consist of trisomy, monosomy X and triploidy. Trisomies were the most common anomaly. While the frequency of trisomy was significantly higher in the older age group (≥35 years) (p=0.001), the frequency of monosomy X and triploidy were higher in the younger age group. Chromosomal changes whose frequencies were not affected by maternal age were structural chromosomal abnormalities and tetraploidies. Conclusion: Since the developing new Technologies are still not affordable enough and their widespread use is limited. As a result, current approaches have indicated that chromosome analysis is still a necessary and useful method. It is thought that detecting the chromosomal anomaly that led to abortion facilitates multidisciplinary patient management and enables to provide more accurate and comprehensive genetic counseling. In cases where the chromosome analysis test is not informative, the application of DNA-based tests such as Quantitative Fluorescence PCR (QF-PCR) and molecular karyotyping may help the diagnosis.