Development of an equine endometrial histology scoring system to complement the Kenney-Doig scale.

The research article presents the development of a new scoring system for endometrial histology in horses to supplement the commonly used Kenney-Doig scale. The new scale takes into account a variety of histological parameters to provide a comprehensive evaluation of uterine biopsies in mares.

Understanding the Kenney-Doig scale

• The Kenney-Doig scale is the standard method used for categorizing uterine biopsies in horses. It’s used to classify and predict the fertility of mares based on the condition of the endometrium.
• However, its objectivity and the level of agreement among pathologists when using the scale have been questioned due to its subjective element. This has prompted the need for a supplement that will enhance reliability.

Gauging Agreement Among Pathologists

• The researchers initially tested the degree of agreement among two pathologists analyzing the same set of 201 uterine biopsies.
• The level of agreement was found to be between slight to moderate, indicating a considerable potential for discrepancy when assessing these biopsies, and therefore, a potential source of error in classification and prognosis.

Development of the New Scoring System

• To improve the objectivity and agreement of biopsy assessments, the researchers developed a numerical scale based on the evaluation of histological parameters.
• The parameters assessed included inflammation, fibrosis, glandular density, and lymphatic lacunae, which are all characteristic features of the endometrial tissue.
• These partial scores were then summed to derive a fifth parameter dubbed ‘Summation’.

Comparison and Correlation with the Kenney-Doig scale

• Upon using the new scoring system together with the Kenney-Doig scale, they found a strong correlation between both scales.
• Incorporating the new scoring system led to a notable increase in the degree of agreement between the two pathologists. This implies that the new scale indeed complements the Kenney-Doig scale and can potentially reduce discrepancies in biopsy assessments.