Fetal Chromosomal Abnormalities and Early Pregnancy Clinical Features

ABSTRACT Background and Aims The aim of this study was to investigate the relationship between fetal chromosomal abnormalities and the clinical features of threatened miscarriage, focusing on cases that underwent chromosomal analysis of the products of conception. Methods This retrospective cohort study was conducted at the University of Yamanashi Hospital in Japan. It included 190 cases of miscarriage before 12 weeks of gestation that underwent uterine evacuation and chromosomal analysis of the products of conception between 2009 and 2023. Cases with unsuccessful cell culture were excluded. Conventional G‐banding karyotyping was performed on all samples. Maternal background and pregnancy information were compared between the fetal chromosomal abnormality group and the normal karyotype group. Further comparisons were made between cases with and without maternal factors in the normal karyotype group. Statistical analysis was performed using the Mann–Whitney U test, Chi‐square test, and Fisher's exact test. Results Out of 190 cases, 137 (72%) had fetal chromosomal abnormalities, and 53 (28%) had normal karyotypes. SCH (chromosomal abnormality group 6.6% vs. normal karyotype group 35%, p < 0.001) and vaginal bleeding (32% vs. 52%, p = 0.01) were significantly more common in the normal karyotype group. No significant differences in maternal background or other pregnancy‐related variables were observed. In the normal karyotype group, no significant differences were noted between cases with and without maternal factors. Conclusion Clinical features, such as SCH and vaginal bleeding, were more common in cases with normal karyotypes than in those with fetal chromosomal abnormalities. Many cases of threatened miscarriage could not be explained by fetal chromosomal abnormalities or maternal factors alone, suggesting the importance of psychological support in the management of these cases.