A Fetus with Imperforate Anus Developing Pulmonary Hypoplasia Triggered by Transient Urethral Obstruction

Figure 4

Schematic of the proposed mechanism of pulmonary hypoplasia in our case. The narrow urethra may have been obstructed due to fetal meconium, which may have passed from the colon into the urethra through the fistula, resulting in complete obstruction of the lower urinary tract in the fetus with urethral stenosis. Urethral obstruction directed the urine flow from the bladder through the rectourethral fistula to the colon, causing oligohydramnios and progression of bowel dilation, resulting in pulmonary hypoplasia.