Occasionally the fertilised egg may implant outside the womb - this is known as an ectopic pregnancy. Most ectopic pregnancies implant in a fallopian tube although they do also occur in the ovaries, cervix or abdomen. But embryos are unable to survive anywhere outside the womb as they do not have the space or nourishment to develop and grow. This means that ectopic pregnancies have to be removed as they pose a great health risk to the mother. In a number of instances, implantation of the ectopic embryo is rejected by the body and naturally removed. But medical attention is often required.
If an ectopic pregnancy proceeds without treatment then the encasing fallopian tube may rupture and cause severe internal bleeding. Symptoms of this include sudden, severe abdominal pain, shoulder pain, dizziness and fainting. Eventually the individual is likely to go into shock. In most cases of treatment, surgery is needed.