Fetal Lower Urinary Tract Obstruction Complicated by Bladder Perforation

A 33-year-old gravida 2, para 0-1-0-0 pregnant woman was referred to our fetal center at 23 weeks and 6 days of gestation with concern for fetal hydrops. Her obstetrical history was significant for a previous emergency cesarean section at 24 weeks’ gestation because of a placental abruption, with the infant’s death occurring at 6 months of age. The current infant had no genetic abnormalities or structural anomalies.

Upon referral, fetal ultrasonography showed large ascites with skin edema and bilateral pleural effusions (Fig 1A), which was consistent with hydrops, and an amniotic fluid index (AFI) of 8 (Figs 1A and 1B). In addition, the bladder wall was observed to have thickened (Fig 1C), which suggested a lower urinary tract obstruction (LUTO). A multidisciplinary team that included the fetal intervention team, neonatology, nephrology, and urology evaluated the woman for possible intrauterine intervention. Fetal echocardiography showed no structural abnormalities, mild tricuspid regurgitation, trivial pulmonary regurgitation, and normal chamber anatomy/systolic function. Fetal magnetic resonance imaging (MRI) revealed bladder outlet obstruction with in utero bladder diverticulum formation and bladder perforation (Fig 2A), explaining the cause of the massive fetal urinary ascites (Fig 2B). In addition, MRI revealed possible pulmonary hypoplasia, duplex morphology of the left kidney with normal renal appearance, with an observed/expected total lung volume of 32%.