Objective: The objective of this study was to compare the frequency and distribution of chromosomal abnormalities with different crown-rump length (CRL) and maternal serum human chorionic gonadotropin (HCG) levels in early miscarriages.
Study design: Pregnancies in which a miscarriage occurred at ≤ 12 weeks' gestation and received karyotyping of chorionic villus after curettage from January 2008 to December 2011 were included in this retrospective study. The frequency and distribution of chromosomal anomalies with different CRLs and HCG levels were compared.
Results: A total of 183 miscarriages were included. The mean maternal age was 32.8 ± 4.6 years, and 37.2% of the subjects were ≥ 35 years of age. Among the 183 miscarriages, 74 (40.4%) cases had a normal karyotype, while 109 (59.6%) were abnormal. Maternal age ≥ 35 years, absence of a history of recurrent miscarriage, and CRL ≥ 15 mm were associated with an abnormal karyotype (p < 0.05). A CRL < 15 mm was associated with other autosomal trisomies (57.7%) and structural abnormalities (11.5%), and a CRL ≥ 15 mm was associated with monosomies (38.7%), triploidies (29%), and viable autosomal trisomies (12.9%).
Conclusions: The frequency and distribution of abnormal karyotypes is different when the CRL is ≥ 15 or < 15 mm at the time of miscarriage.
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