Relationship between uterine biopsy score, endometrial infection and inflammation in the mare.

This study investigates the link between the health of a mare’s uterus, as determined by an endometrial biopsy score, and rates of inflammation and infection. The results suggest an increased likelihood of these conditions in mares with certain biopsy scores.

Objective and Methodology

• The primary goal was to understand the relationship between endometrial biopsy scores – a measure of uterine health and fertility prospects – and three key indicators: presence of polymorphonuclear cells (PMNs) in the epithelium, presence of PMNs in cytology, and presence of infection in microbiology.
• The researchers studied a group of 69 mares suspected of subclinical endometritis (unsuccesful breeding attempts in the same season) and a control group of 15 maiden mares for comparative purposes.
• The data for the examination was obtained through procedures such as endometrial biopsy and cytobrush technique, which allows for the collection of cells from the surface of the uterus.

Results

• The study found that 64 out of 82 mares, or 78%, exhibited endometrial changes as reflected in endometrial biopsy scores. This indicates a strikingly high incidence of uterus-related health issues in the sample group.
• There was a recorded increase in the incidence of PMNs for those mares with higher biopsy grades (IIA, IIB, and III). This demonstrates a clear correlation between the biopsy score and presence of PMNs.
• Significant statistical differences were discovered between grade I and IIA and grades I and IIB mares regarding PMN infiltration. Furthermore, similar differences were found in microbiological and cytological examinations, all suggesting a relationship between biopsy scores and the level of infection.
• It was observed that mares with grades IIA and IIB had the highest rate of infection, further highlighting the connection between poor biopsy results and an increased likelihood of uterine issues.
• However, there were no statistical significant differences recorded when comparing the rates of endometrial infection in horses with biopsy scores I, IIA, IIB, and III, using the cytobrush technique.

Conclusions

• The research concluded that degenerative changes in the endometrium could make mares more prone to uterine infection and inflammation.
• Additionally, mares with better endometrial scores (grade I) were found to be less susceptible to infection than those with poorer biopsy results (grades IIA, IIB, and III).
• It is also reaffirmed that the endometrial biopsy can be a reliable tool to help evaluate a mare’s risk for infection and potential fertility issues.