Karyotyping of products of conception from a sporadic first-trimester miscarriage shows a chromosomal abnormality. Which type is the MOST common overall?

• A Monosomy X (45,X)
• B Triploidy
• C Balanced Robertsonian translocation
• D Autosomal trisomy ✓

Explanation

Among chromosomally abnormal first-trimester abortuses, autosomal trisomies form the largest group, accounting for roughly half of all abnormal karyotypes, with trisomy 16 being the most frequent single trisomy. Monosomy X is the single most common specific anomaly but is outnumbered by the trisomies taken together. Balanced parental translocations cause recurrent rather than sporadic loss, and triploidy is less frequent than either group.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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