To improve clinicians' understanding, and to explore the diagnosis and treatment of pregnancy complicated with patent urachus. The clinical symptoms, ultrasound images, and delivery outcome of the pregnancy complicated with patent urachus were reported, and the literature was reviewed. The patient had umbilical leakage as a young child occasionally, the symptom of leakage was not obvious after she was 10 years old, and there was no asymptomatic before pregnancy and in the first and second trimesters. Umbilical leakage was present at gestational 33 weeks, and ultrasound showned a tubular structure (0.7 cm in width) was connected between the top of the bladder and the umbilicus, and there was anechoic areas inside. The pregnancy complicated with patent urachus was diagnosed. The patient was checked regularly, and kept the umbilicus clean and dry. Premature rupture of membranes occured at gestational 39 weeks 4 days. The patient was admitted to the obstetrics department, and she deliveried finally. After delivery, the symptoms of umbilical leakage urine relieved, and an elective resection of abnormal urachus was planned. The patent urachus creates a tube connection between the umbilicus and the anterosuperior wall of the bladder, it was termed an median umbilical ligament at birth as usual, which still communicated with the bladder after birth. The main clinical manifestations were umbilical leak and infection, which were the main diagnostic basis. Ultrasound, CT and MRI were important auxi-liary examination methods.The patients with symptoms in the neonatal and early childhood period were managed actively and had the potential for self resolution, especially for the children younger than 1 year. Therefore, patients under 1 year of age were offered surgery only if they had recurrent infections or failed to selfresolve. It is recommended to remove abnormal urachus before pregnancy for the women complica-ted with patent urachus. If the patent urachus was found during pregnancy, the umbilicus should be kept clean and dry to avoid infection. The pregnancy complicated with patient urachus is not contraindicated to vaginal delivery.