Clinic for Gynecology and Obstetrics, University Clinical Center of Serbia.
Faculty of Medicine, University of Belgrade.
Clin Dysmorphol. 2024 Jul 1;33(3):137-144. doi: 10.1097/MCD.0000000000000496. Epub 2024 Feb 16.
Fetuses with abnormal karyotypes often exhibit distinctive ultrasonographic markers, including major anomalies and "soft" markers, indicating potential chromosomal issues. A crucial consideration arises when a single fetal anomaly is detected, raising the question of whether karyotyping is warranted, given the associated procedural risks. Our objective was to establish correlations between single fetal anomalies identified through ultrasound and chromosomal abnormalities.
A cross-sectional study analyzed the karyotype of 1493 fetuses and detected a single ultrasonographic anomaly over a 16-year period. Karyotyping was performed using the standard karyotype technique. Moreover, data regarding the type of anomaly detected ultrasonographically, karyotype results, and outcomes following interventions were collected. Among other methods, the use of positive likelihood ratios (LR+) was used to evaluate the diagnostic accuracy of ultrasound compared to karyotyping.
In total, an aberrant karyotype was identified in 99 fetuses (6.6%). This was most commonly observed in cases involving a "soft" marker, occurring in 27 out of 218 fetuses (12.4%). The most frequently detected aberrant karyotype resulted from aneuploidies (80.6% of cases), notably trisomy 21 (50.5%). "Soft" markers predicted chromosomal issues (LR+ = 1.9; OR = 2.4), and isolated polyhydramnios (LR+ = 1.54; OR = 1.6) showed significance in predicting fetal chromosomal aberrations.
When assessing the necessity for karyotyping in fetuses with single major anomalies or "soft" markers, it is crucial to consider individual risks for chromosomopathies, including the LR+ of the detected marker. In cases where fetuses exhibit isolated anomalies with a normal karyotype, additional diagnostic measures, such as molecular cytogenetic and molecular genetics techniques, may become necessary.
染色体异常的胎儿常表现出独特的超声标志物，包括主要畸形和“软”标志物，提示潜在的染色体问题。当发现单一胎儿异常时，需要考虑是否进行染色体核型分析，因为这涉及到相关的操作风险。我们的目的是确定超声检查发现的单一胎儿异常与染色体异常之间的相关性。
采用横断面研究分析了 1493 例胎儿的核型，在 16 年的时间内发现了单一超声异常。采用标准核型技术进行核型分析。此外，还收集了超声检测到的异常类型、核型结果以及干预后的结果等数据。除其他方法外，还使用阳性似然比（LR+）来评估超声检查相对于核型分析的诊断准确性。
共有 99 例（6.6%）胎儿存在异常核型。最常见的是“软”标志物异常，在 218 例胎儿中有 27 例（12.4%）。最常见的异常核型是染色体非整倍体（80.6%的病例），尤其是 21 三体（50.5%）。“软”标志物可预测染色体异常（LR+ = 1.9；OR = 2.4），孤立性羊水过多（LR+ = 1.54；OR = 1.6）对预测胎儿染色体异常具有显著意义。
在评估具有单一主要畸形或“软”标志物的胎儿是否需要进行核型分析时，必须考虑染色体病的个体风险，包括检测标志物的 LR+。对于具有正常核型的孤立性异常胎儿，可能需要进行其他诊断措施，如分子细胞遗传学和分子遗传学技术。
