Abstract
Introduction: Postpartum hemorrhage (PPH) is the main cause of maternal mortality, ranging from 18%–50% of deaths worldwide. Secondary postpartum hemorrhage (SPPH) is defined as bleeding 24 hours to 12 weeks after delivery. Clinically worrisome uterine hemorrhage develops within 1 to 2 weeks in perhaps 1 percent of women. Such bleeding most often is the result of abnormal involution of the placental site. In some cases, uterine involution is hindered because of infection, retained placental tissue, or other causes. Such subinvolution is accompanied by varied intervals of prolonged lochia as well as irregular or excessive uterine bleeding. Another cause of subinvolution is incompletely remodeled uteroplacental arteries. These noninvoluted vessels are filled with thrombosis and lack an endothelial lining. Perivascular trophoblasts are also identified in the vessel walls, suggesting an aberrant interaction between uterine cells and trophoblasts. Secondary postpartum hemorrhage is most commonly associated with endometritis and retained products of conception, particularly retained placental tissue. However, this case highlights an uncommon mechanism of secondary postpartum hemorrhage associated with a retained intrauterine blood clot, which causes incomplete spiral artery remodeling. Case: A 36-year-old woman with approximately 2,000 mL of bleeding 9 days after elective cesarean delivery. Ultrasonography examination showed a blood clot in the uterus measuring 10.77 x 12.85 cm; a 700 mL blood clot was removed from the uterus by suction curettage. Postoperative ultrasound evaluation found the uterus in good condition without blood clots. Discussion: In this case, the retained blood clot is attributed to obstructed uterine outflow resulting from the lack of prior dilatation of the internal os, rather than to retained placental tissue. Consequently, this case offers an opportunity to discuss retained intrauterine blood clots as a rare and potentially underrecognized mechanism of secondary postpartum hemorrhage following cesarean delivery. Conclusion: In this case, secondary postpartum hemorrhage was caused by uterine subinvolution resulting from the retention of blood clots within the uterus, which prevented complete remodeling of the uteroplacental arteries.