Sperm aneuploidy and recurrent pregnancy loss

Area of Science:

• Reproductive Biology
• Human Genetics
• Cytogenetics

Background:

• Recurrent pregnancy loss (RPL) affects couples trying to conceive.
• Sperm chromosome abnormalities, including aneuploidy and diploidy, are potential contributors to RPL.
• The relationship between semen quality and sperm chromosome abnormalities in RPL requires further investigation.

Purpose of the Study:

• To investigate sperm chromosome aneuploidy and diploidy rates in men from couples with recurrent first trimester abortions.
• To assess the correlation between sperm chromosome abnormalities and semen quality in men with RPL.
• To determine if specific chromosome aneuploidies are associated with RPL.

Main Methods:

• Double and multicolour fluorescence in-situ hybridization (FISH) on sperm samples from 20 couples with RPL.
• Analysis of chromosomes 1-17, 8-18, sex chromosomes, and a subset including 4, 7, 12, 13, 15, 21, and 22.
• Comparison of aneuploidy/diploidy rates between men with and without RPL, and with varying semen quality.

Main Results:

• Markedly high sperm disomy rates (14.5-15.5%) were observed in 2 out of 20 cases.
• Elevated cumulative disomy rates (7.8-9.5%) for specific chromosomes were found in 3 additional patients.
• Significantly elevated sperm aneuploidy (30-34%), but not diploidy, was found in 10% of men with RPL, particularly those with poor semen quality.

Conclusions:

• A subset of men with RPL exhibit increased sperm aneuploidy, potentially contributing to pregnancy loss.
• Poor semen quality independently increases sperm aneuploidy and diploidy rates, confounding RPL investigations.
• Further research is needed to clarify the causal link between specific sperm chromosome abnormalities and RPL.