Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Prominent fetal calyces means that there could be obstruction in the urinary tract outflow. In such cases, followup is advised. If there is change and pregnancy continues then no intervention is done and ultrasound of the fetus is done after delivery. if it causes symptoms then plan is decided accordingly. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. Wishing you good health.