An exploratory study on the placental efficiency, histomorphometric characteristics, hormonal shifts, and oxidative stress in dromedary camels with dystocia

The study investigated placental efficiency, histomorphometry, and hormonal concentrations (progesterone, estradiol 17β, and cortisol) alongside oxidative stress indicators (malondialdehyde (MDA) and total antioxidant capacity (TAC)) and performed correlation analyses among these parameters in eutocia, dystocia, and uterine inertia deliveries in dromedary camels. A total of 24 pregnant dromedary camels, aged 8-11 years, with an average body weight of 520 ± 75 kg, were categorized into three groups based on parturition outcome: the eutocia group (EG), <i>n</i> = 12; the dystocia group (DG), <i>n</i> = 5; and the uterine inertia group (UIG). <i>n</i> = 7. The results revealed significantly lower (<i>p</i> < 0.05) syncytiotrophoblast layer thickness, chorionic villi length and diameter, and syncytiotrophoblast layer integrity in dystocia deliveries. Additionally, the inflammatory cell infiltration was higher (<i>p</i> < 0.01) in DG than in UIG and EG. The placentas from EG had long, slender, and highly vascularized chorionic villi, while in DG placentas, the villi were shorter and atrophied. Progesterone concentrations were significantly higher (<i>p</i> < 0.01) in DG compared to UIG and EG. While DG had the lowest mean estradiol-17β concentration, EG had the highest. Moreover, MDA and TAC concentrations were lowest in the EG group, followed by the UIG group and then the DG group. Additionally, a positive correlation was found between chorionic villi diameter and placental efficiency, and between placental efficiency and vascular density. There were negative correlations among hormonal, antioxidant, placental efficiency, and histomorphometry parameters, as well as among these parameters and inflammatory cell infiltration. In conclusion, dystocia in camels was associated with hormonal dysregulation, presumably oxidative stress, and placental structural damage. However, for a definitive and powerful outline, further studies on large and more balanced populations are necessary in the future.