Light micrograph of a human fallopian tube showing a tubal ectopic pregnancy. An ectopic or extrauterine pregnancy is the development of a foetus at a site outside of the womb, most commonly in a fallopian tube. The interior (lumen) of the tube (top part of image) becomes filled with developing embryo, placenta & associated membranes. The tubal wall (bottom) may become congested and thinned. Ectopic pregancies usually become apparent by severe haemhorrage (bleeding) into the interior of the tube (bright red areas on image), presenting as surgical emergencies. In a few cases, development progresses to a stage where a live baby may be delivered by Caesarean section.