Maternal age, history of miscarriage, and embryonic/fetal size are associated with cytogenetic results of spontaneous early miscarriages.

PURPOSE: To clarify the associations of the maternal age, history of miscarriage, and embryonic/fetal size at miscarriage with the frequencies and profiles of cytogenetic abnormalities detected in spontaneous early miscarriages.

METHODS: Miscarriages before 12 weeks of gestation, whose karyotypes were evaluated by G-banding between May 1, 2005, and May 31, 2017, were included in this study. The relationships between their karyotypes and clinical findings were assessed using trend or chi-square/Fisher's exact tests and multivariate logistic analyses.

RESULTS: Three hundred of 364 miscarriage specimens (82.4%) had abnormal karyotypes. An older maternal age was significantly associated with the frequency of abnormal karyotype (ptrend  < 0.001), particularly autosomal non-viable and viable trisomies (ptrend 0.001 and 0.025, respectively). Women with ≥ 2 previous miscarriages had a significantly lower possibility of miscarriages with abnormal karyotype than women with < 2 previous miscarriages (adjusted odds ratio [aOR], 0.48; 95% confidence interval [95% CI], 0.27-0.85). Although viable trisomy was observed more frequently in proportion to the increase in embryonic/fetal size at miscarriage (ptrend  < 0.001), non-viable trisomy was observed more frequently in miscarriages with an embryonic/fetal size < 10 mm (aOR, 2.41; 95% CI, 1.27-4.58), but less frequently in miscarriages with an embryonic/fetal size ≥ 20 mm (aOR, 0.01; 95% CI, 0.00-0.07) than in anembryonic miscarriages.

CONCLUSIONS: The maternal age, history of miscarriage, and embryonic/fetal size at miscarriage may be independently associated with the frequencies or profiles of cytogenetic abnormalities in early miscarriages.