Innervation of the Uterus: An Anatomical Study With Application to Better Understanding Pelvic Pain in Women

Pelvic pain has a significant impact on quality of life, especially when associated with benign pelvic diseases, such as endometriosis or chronic conditions leading to persistent discomfort. A substantial proportion of women are affected in their reproductive years, making it a public health issue. Even though previous research has provided a map of intrauterine innervation, the origins and pathways of macro-uterine innervation are still poorly understood. A better understanding of the complex network of pelvic nerves is crucial for improving surgical techniques and patient outcomes. We performed immunohistochemistry on pelvic slices of four human fetuses by using a wide variety of neuronal markers. Then, a 3D reconstruction was performed, and the different anatomical structures were identified, as well as the path of the nerve fibers toward the uterus, and nerve specificity was determined. Our findings confirmed that the nerve fibers essential to uterine function and pelvic sensitivity mainly originate from the inferior hypogastric plexus, branching extensively to innervate the uterus, cervix, and surrounding pelvic structures. Two main pathways were identified, one medial and the other anterolateral to the ureter. Considering these pathways during surgical interventions is paramount as their integrity might inadvertently be impacted, leading to postoperative complications, such as pain or functional disorders. The implications of this research extend beyond the operating room, as they will undoubtedly enrich both clinical practice and medical education in the years to come.