Effect of Dystocia Duration on the Placental Health in Canines

The study aimed to determine whether placental lesions differ according to the duration of dystocia. Forty-seven placentas were obtained from 18 bitches that underwent emergency cesarean sections. For descriptive purposes, the cases were classified into four groups based on the duration of dystocia: Group A, up to 6 h; Group B, 6-11.9 h; Group C, 12-24 h; and Group D, more than 24 h. Forty-seven placentas were studied. Both macroscopic and microscopic characteristics were evaluated in each placenta. Descriptive data were presented, and logistic and multinomial regression models were used to assess whether dystocia duration (in hours) is associated with the presence and severity of placental macro- and microscopic lesions. An hour increment over the mean in the duration of dystocia showed a non-significant trend to increasing the presence of macroscopic necrosis (OR: 1.11, p = 0.09) and mineralization (OR: 1.10, p = 0.06), and it also increased the severity of macroscopic congestion (OR: 1.44; p = 0.01) and showed a non-significant trend to increasing the severity of polymorphonuclear neutrophil infiltrate (OR: 1.18; p = 0.06). These findings highlight the importance of early obstetric intervention in all cases of dystocia to minimize fetal hypoxia and improve neonatal outcomes. Moreover, the placenta could serve as a biomarker for fetal distress, as the presence of severe lesions indicates an increased risk for reduced neonatal survival.