The detection of a patent urachus and allantoic cyst of the umbilical cord on prenatal ultrasonography

Prenatal ultrasonography is used routinely in the evaluation of high-risk pregnancy and in the evaluation of feta] development. Ultrasonographic detection of an umbilical cord allantoic cyst and a patent urachus has been described previously, 0 but it is unusual to visualize both congenital anomalies clearly in the same fetus. We report a case in which both a patent urachus and an allantoic cyst were demonstrated on prenatal ultrasonography.