Recurrent abruptio placentae in a cynomolgus monkey (Macaca fascicularis)

Introduction: Abruptio placentae, defined as premature separation of a normally implanted placenta, is a life threatening pregnancy complication with unknown pathophysiology. A history of abruptio placentae is the major risk factor for this pregnancy complication in humans. We describe the first case of recurrent abruptio placentae in a Macaca fascicularis. Material and methods: A pregnant M. fascicularis at term gestation was presented with weakness and hypothermia. Cesarean section revealed retroplacental hemorrhage with partial placental separation from the uterus. Results: The weight of the female fetus was within the lower birth weight range for these species. The maternal side of placenta contained necrotic tissue, occupying approximately 60% of the maternal surface. The placental implantation bed demonstrated neutrophil infiltration. Perivascular collections of lymphocytes were noticed in the uterine smooth muscle. Conclusion: This case report underlines the importance of neutrophil infiltration and uterine venous drainage in the cascade of events leading to abruptio placentae.