If the pregnant woman has a history of nephrolithiasis, recurrence should be suspected. Stones, usually forming late in pregnancy, are problematic. Since radiation-based imaging techniques cannot be used during pregnancy, only ultrasound should be used to monitor kidney swelling. The mother's pain and the degree of kidney swelling should be closely monitored. If pain increases or kidney swelling worsens, an endoscopic procedure should be considered to address the possibility of a ureteral stone.