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.

Keywords

• Karyotyping
• habitual abortion
• spontaneous abortion
• maternal age
• chromosomal aberrations

Gebelik Kaybında Kromozom Analizinin Zorlukları: 1208 örnek deneyiminden çıkarılan dersler

Abstract

Amaç: Önceki çalışmalar spontan düşüklerin yarısının fetal kromozomal anormallikler ile ilişkili olduğunu göstermiştir, ancak gebelik kayıplarının nedenlerini ortaya koymak her zaman mümkün değildir. Bu çalışmanın amacı, gebelik kayıplarında kromozom anormalliklerinin sıklığını ve kültür başarısızlık oranlarını araştırmak ve elde edilen sonuçları, literatürdeki benzer çalışmaları karşılaştırmaktır. Gereç ve Yöntemler: Haseki Eğitim ve Araştırma Hastanesi Genetik Tanı Merkezi'ne Ağustos 2016-Şubat 2021 tarihleri arasında kabul edilen, abortus materyali koryon villus örneklerinin uzun süreli kültürlerinden elde edilen 1208 adet düşük materyalinin karyotip analiz sonuçları retrospektif olarak değerlendirildi. Bulgular: Materyallerin yaklaşık yarısında kültür başarısızlığı nedeniyle sonuç elde edilemedi. Trizomi, monozomi X ve triploididen oluşan anormal karyotiplerin %87'sinde (116) sayısal anomaliler gözlendi. Trizomiler en sık görülen anomali iken, ileri yaş grubunda (≥35 yaş) trizomi sıklığı anlamlı olarak daha yüksek, genç yaş grubunda monozomi X ve triploidi sıklığı daha yüksekti. Sıklıkları anne yaşından etkilenmeyen kromozomal değişiklikler, yapısal kromozomal anormallikler ve tetraploidiler idi. Sonuç: Gelişen yeni teknolojilerin henüz yeterince ucuz olmaması ve yaygın kullanımlarının sınırlı olması nedeniyle güncel yaklaşımlar, kromozom analizinin hala gerekli ve yararlı bir yöntem olduğunu ortaya koymuştur. Düşüklere neden olan kromozomal anomalilerin saptanmasının multidisipliner hasta yönetimini kolaylaştıracağı aşikardır. Kromozom analizi testinin bilgi verici olmadığı durumda ise kantitatif floresan PCR (QF-PCR), moleküler karyotipleme gibi DNA temelli testlerin uygulanması tanıya yardımcı olabilmektedir.

Keywords

• Karyotipleme
• habituel abortus
• spontan abortus
• anne yaşı
• kromozom anomalisi.

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