Novel Insights into Normal Karyotype Miscarriage: Distinctive Patterns and Implications for Diagnosis Based on Next‐Generation Sequencing Analysis

ABSTRACT Purpose This study aimed to identify the clinical differences between normal and abnormal karyotype miscarriages and evaluate whether clinical findings could predict the presence or absence of chromosomal abnormalities. Methods A total of 117 patients with early miscarriage who underwent chorionic villus chromosomal testing using next‐generation sequencing were retrospectively analyzed. Clinical findings were compared between the normal (euploid; n = 47) and abnormal karyotype (aneuploid; n = 70) groups. Results Normal karyotype miscarriages occurred significantly more often before yolk sac visualization (29.8% vs. 0%, p < 0.0001) and before fetal heartbeat confirmation (51.1% vs. 15.7%, p = 0.0001) than abnormal karyotype miscarriages. The mean crown–rump length was larger in the normal karyotype group (15.3 ± 8.2 mm vs. 11.8 ± 6.8 mm, p = 0.037). Normal karyotype miscarriages exhibited a bimodal distribution in gestational age at miscarriage. In addition, the normal karyotype was associated with a history of two or more biochemical pregnancy losses (21.3% vs. 7.1%, p = 0.045). Conclusion Distinct clinical and ultrasonographic patterns were observed in normal and abnormal karyotype miscarriages. These features have limited diagnostic value, and their usefulness in supporting counseling or decision‐making is also limited when genetic testing is not available.