An ectopic pregnancy occurs when a fertilized egg attaches somewhere outside the uterus. An untreated ectopic pregnancy can be a medical emergency. Discover signs of ectopic pregnancy: Ada doctors explain early symptoms, causes, diagnosis, and treatment options. Stay informed for better health. An ectopic pregnancy takes place when a fertilized egg attaches to an area other than the uterus, most often in the fallopian tubes. Also known as tubal pregnancy, this type of pregnancy cannot proceed normally because the fertilized egg cannot survive outside the uterus. Ectopic pregnancy occurs when a fertilized egg attaches outside the uterus, often in a fallopian tube. Ectopic pregnancies can cause serious complications and always require treatment. If you have symptoms of an ectopic pregnancy, seek immediate medical attention.