Doctors in BBC's Call The Midwife explain rare pregnancy complication

One of the conditions which has been in the spotlight recently is ectopic pregnancy, a life-threatening condition which is the leading cause of maternal death in the first trimester of pregnancy. It occurs when an embryo grows in the fallopian tube, rather than the womb. The uterus is the only organ designed to stretch, supply blood and safely support a developing pregnancy. When implantation occurs elsewhere, the pregnancy cannot develop normally and poses significant risks to the mother.