What is the most common chromosomal abnormality associated with spontaneous abortions?

The most common chromosomal abnormality associated with spontaneous abortions is known to be the presence of chromosomal anomalies, particularly those affecting embryonic growth and development. In the case of spontaneous abortions, Turner syndrome, which is characterized by the absence of one X chromosome (45,X), is frequently identified in early gestational losses. This chromosomal abnormality is particularly relevant because it leads to significant developmental issues, making it unlikely for the embryo to progress to term.

Other chromosomal abnormalities, such as Down syndrome (Trisomy 21), Patau syndrome (Trisomy 13), and Klinefelter syndrome (47,XXY), do occur, but they are less commonly implicated in the early pregnancy loss context. Down syndrome, for example, is generally associated with live births rather than early miscarriage, while Patau and Klinefelter syndromes are not as prevalent in the context of spontaneous abortions. Therefore, the link between Turner syndrome and early pregnancy loss is a significant factor in understanding the prevalence of chromosomal abnormalities in spontaneous abortions.