My Sister's Baby Is Growing Outside Her Uterus...?

To make my long story short, my sister is pregnant. She is about 180 and 5'10. Her baby was doing fine until we found out that the baby is growing on the outside of her uterus. She told me that she has to have an abortion now and that if she decided to have the baby she would die. So my question is... is this somehow reversible or is there some way that we can save the baby without putting her life in jeopardy?