Postpartum glycogen content in the myometrium of female Sprague-Dawley rats fed a diet rich in fats and sugars Objectives: The objectives of this research were to use the histochemical method of periodic acid Schiff staining (PAS) to stain the uterine tissues of rats fed a high-fat and high-sugar diet (HFHSD) and a standard diet (SD), and to quantify and compare the content of postpartum glycogen in the myometrium of both groups of Sprague- Dawley rats. Study desing: Experimental research on an animal model – the case-control study. Materials and methods: The study was made on the archive of maternal tissues collected as part of the study RECOOP-CMSC Senior Scientist (RCSS) Grant 2018-2020 #012: "The role of obesity-induced low-grade inflammation in the adipokine signaling in pregnant rat uterus". Ten female Sprague-Dawley rats were divided into two groups. The control group consisted of SD Sprague-Dawley women, and the experimental group consisted of HFHSD women who received this diet from the 3rd week of life. The presence of glycogen granules was analyzed by PAS staining. The maternity tissue was first fixed in a 4% buffered formaldehyde solution, followed by embedding in paraffin blocks. The 5 µm thick sections obtained, after deparaffinization, were stained with the PAS method. This was followed by photo analysis and comparison of statistical results. Results: In the outer layer of the myometrium between the SD and HFHSD groups, a statistically significant difference in glycogen levels was found (p = 0.016), in contrast to the inner layer of the myometrium, where the limit value was determined. Conclusion: Increased levels of glycogen in the outer myometrium in the HFHSD group compared to the SD group show that this layer of the uterus is more sensitive to the diet than the inner layer.