Obstetric DIC, which occurs in 0.03 ~ 0.35% of pregnancies, is the leading cause of maternal and neonatal death worldwide (13). In most cases, obstetric DIC occurs secondary to placental abruption, amniotic fluid embolism, preeclampsia, HELLP syndrome, or postpartum haemorrhage. In these cases, DIC was mostly caused by consumption or dilutional coagulopathy. In our case, blood examination revealed extremely low fibrinogen and high D-dimer levels, indicating enhanced fibrinolytic-type DIC. The DIC score was only positive for the basic criteria defined by the JSTH, but did not meet the criteria for either obstetrical DIC or infectious DIC. Therefore, the consumption coagulopathy in our case was thought to have initiated secondary to leiomyoma degeneration. Consumption coagulopathy due to leiomyoma degeneration is rare, with only five cases reported in the English literature (14). Consumption coagulopathy induced by degenerated leiomyoma during pregnancy is even rarer, and only two cases have been reported (15). In all these previous reports, signs of enhanced fibrinolytic-type DIC were observed. All previous cases required surgical removal to resolve the consumption coagulopathy, and the pathological findings of these cases revealed multiple infarctions with thrombi in the leiomyoma (15, 16). Kitao et al. suggested that acute degeneration of leiomyomas might damage the endothelial cells of the vessel, which activates the consumption of coagulation factors and platelets; then, thrombin and plasmin might be released into the circulation and finally activate fibrinolysis. In general, enhanced fibrinolytic-type DIC increases the risk of haemorrhagic events; however, none of the leiomyoma degeneration-oriented consumption coagulopathies, including our case, experienced massive haemorrhage. In our case, abnormal vaginal bleeding at admission that was not accompanied by shortening of the cervical length might have been a sign of abnormal coagulation-fibrinolysis conditions.
The perinatal outcomes of patients with coagulopathy during pregnancy were poor. Not to speak of obstetrical DIC, in the previous cases of consumption coagulopathy due to leiomyoma degeneration, the patient went through preterm delivery (9). To our knowledge, this is the first report of successful continuation of pregnancy without obstetric complications. This suggests that prompt evaluation of blood tests, including coagulation factors, in the acute phase of leiomyoma degeneration as well as the immediate use of blood preparations are recommended before the situation worsens, especially when abnormal bleeding is observed. However, in this case, a new complication, PVL, arose as a possible complication of consumption coagulopathy during pregnancy. It can also cause long-term neurodevelopmental disorders. PVL is white matter brain damage that is mainly attributed to hypoxia and inflammation (17). The preterm brain is susceptible to PVL formation, with the most susceptible interval at 24–32 weeks of gestation, in which cerebral white matter axons are in the rapid growth phase (18). The lesion becomes visible 1–2 weeks after onset. In our case, because the PVL lesion was already visible on day 6, the timing of PVL formation was estimated to be before the onset of labour. The most probable period for the development of PVL is at 17–18 weeks of gestational age, when severe inflammation and consumption coagulopathy developed. However, these periods were too early for white matter neurodevelopment, and therefore, unlikely for PVL formation. Another possibility is that hypoxia due to leiomyoma degeneration may have persisted long after the recovery from consumption coagulopathy. Regarding the placental pathological findings, syncytial nodules and chorangiosis, which are often observed in the placenta during preeclampsia, maternal diabetes, and fetal growth restriction, indicate an adaptive response to chronic intrauterine hypoxia (19). Acute intrauterine hypoxia may have occurred during the period of severe inflammation and consumption coagulopathy, and chronic intrauterine hypoxia may have been caused by insufficient blood supply to the placenta due to a large leiomyoma throughout the pregnancy period. Continuous chronic hypoxia following an acute event may be a second cause of PVL formation.
We report a case of pregnancy complicated by consumption coagulopathy due to a degenerated leiomyoma. Unlike previous reports, the pregnancy in our case lasted until full term after the patient recovered from consumption coagulopathy by transfusion of blood preparations. However, consumption coagulopathy may have induced chronic intrauterine hypoxia and affected the infant’s brain development. The fact that the continuation of pregnancy was possible even after consumption coagulopathy without removing the degenerated leiomyoma is a new finding; however, the limitation of this study is that we could not confirm a direct relationship between the degenerated leiomyoma and consumption coagulopathy without a pathological study of the leiomyoma. Consumption coagulopathy during pregnancy, not due to obstetrical causes, is rare, but the degeneration of a leiomyoma during pregnancy is a common condition for those who have large leiomyomas. We need to be aware of the possibility that pregnancy complicated by a large leiomyoma could cause severe hypoxia and inflammation, which might be attributed to poor prenatal outcomes and/or permanent neurodevelopmental disorders in newborns.