An ectopic pregnancy occurs when a fertilized egg attaches somewhere outside the uterus. An untreated ectopic pregnancy can be a medical emergency. An ectopic pregnancy often occurs when a fertilized egg has trouble passing through the fallopian tube. Here’s what to know about symptoms, diagnosis and care. Ectopic pregnancy definition Ectopic pregnancy is a complication of the pregnancy that is characterised by the growth of the fertilized egg (embryo) outside of the uterus. This complication commonly occurs (90%) in a fallopian tube and less commonly occurs in the ovary, cervix, or abdominal cavity. In a healthy pregnancy, the embryo implants itself in the uterus, but in ectopic pregnancy, the embryo implants outside of the uterus. This fertilized egg (embryo) cannot survive due to the lack ... 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.