Placental Fetal Thrombotic Vasculopathy Occurring in Association with Megacystis-microcolon-intestinal Hypoperistalsis Syndrome: A Case Report.

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare disease of functional obstruction affecting the bladder and intestines, characterized by a markedly distended bladder, microcolon, and decreased or absent intestinal peristalsis. Afflicted neonates have very poor prognosis, usually with fatal outcomes in first days to months of life. Placental fetal thrombotic vasculopathy (FTV) is a thrombo-occlusive disorder of the chorionic plate and fetal circulation. Herein, we describe an undocumented association of MMIHS and placental FTV. We present the case of 32-year-old female G4P2-0-1-2, who gave birth to a viable female infant at 35 weeks of gestation via spontaneous vaginal delivery. Fetal MRI, completed at 24 weeks of gestation, revealed a massively distended urinary bladder, bilateral hydronephrosis in the presence of normal amniotic fluid, and poorly visualized bowel loops without meconium extending into the rectum. Given the constellation of these findings, a presumptive diagnosis of MMIHS was established. After birth, the neonate presented with clinical and radiological features consistent with MMIHS. An intact placenta was delivered and macroscopic examination showed numerous thrombi in fetal vasculature. Microscopic examination showed thrombosis and recanulization of fetal vessels in stem villi and histologic changes consistent with placental FTV. Neonatal course was complicated by hypoglycemia, malrotation, anemia, thrombocytopenia, and coagulopathy. The infant was subsequently discharged home with hospice and palliative care. To our knowledge, this is the first case of MMIHS associated with placental FTV documented in the English literature. Our report illustrates the value of pathological examination of the placenta in this rare disease.