Scoring of sperm chromosomal abnormalities by manual and automated approaches: qualitative and quantitative comparisons

Abstract

It is now well known that levels of sperm disomy correlate to levels of infertility (as well as other factors). The risk of perpetuating aneuploidy to the offspring of infertile males undergoing intracytoplasmic sperm injection (ICSI) has become a hotly debated issue in assisted reproduction; however, there remain barriers to the practical implementation of offering sperm disomy screening in a clinical setting. The major barrier is the operator time taken to analyze a statistically meaningful (sufficient) number of cells. The introduction of automated 'spot counting' software-hardware combinations presents a potential solution to this problem. In this preliminary validation study, we analyzed 10 patients, both manually and using a commercially available spot counter. Results show a statistically significant correlation between both approaches for scoring of sperm disomy, but no correlation is found when scoring for diploid sperm. The most likely explanation for the latter is an apparent overscoring of two closely associated sperm heads as a single diploid cell. These results, and similar further studies that will ensue, help to inform cost-benefit analyses that individual clinics need to carry out in order to decide whether to adopt sperm aneuploidy screening as a routine tool for the assessment of sperm from men requiring ICSI treatment.

Figure 1

Normal sperm head with single X (Green) and 18 (Aqua) chromosomes, as scored by the automated spot counter.

Figure 2

Percentage of cells scored manually (x-axis) vs. automated scoring (y-axis) for (A): Total disomy—R²= 0.364; P = 0.0644; (B): Sex chromosome disomy—R²= 0.529; P = 0.0170; (C): Disomy 18—R² = 0.443; P = 0.0356 and (D): Diploidy—R² = 0.012; P = 0.7628.