What is the most common category of chromosomal abnormality found in first-trimester spontaneous abortions?

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

Explanation

About half of first-trimester abortuses are chromosomally abnormal, and autosomal trisomies form the largest single category, accounting for roughly half of these; trisomy 16 is the most common individual autosome. Monosomy X is the most common single abnormality in an individual abortus, which makes it the tempting distractor, but as a category the trisomies together far outnumber it. Balanced translocations are usually compatible with survival and cause recurrent loss through parental carriers.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.