There is a small fraction of ectopic pregnancies called abdominal pregnancies, where the fetus and placenta implant on some abdominal structure rather than inside of the tube. The implantation on the liver that you mention would be considered an abdominal pregnancy. Abdominal pregnancies are approximately 1% of ectopics. In rare situations these pregnancies have continued on and are delivered at laparotomy. Abdominal pregnancy exceedingly dangerous for the mother, as without a uterus between the placenta and the mother the vascular anatomy can be very bizarre. In some cases there can be near aorta sized new blood vessels going into the abdominal pregnancy, which at the time of delivery can lead to massive hemmorhage. Usually the baby is delivered and the placenta is left in place, as its vascular attachment to the mother can be difficult if not impossible to separate without huge life threatening bleeding. In many cases the placenta will eventually dissolve, sometimes with the help of methotrexate injections, though this process can be fraught with complications.

Though there have occasionally be cases of abdominal pregnancies going to term, these are the exception rather than the rule, and usually are the result of failing to diagnose the abdominal pregnancy early. In some cases the abdominal pregnancy can eventually look so much like an intrauterine pregnancy that it is indistinguishable on ultrasound. If an abdominal pregnancy is identified early, typically it will be removed via laparoscopy or laparotomy, or if very early treated with methotrexate. These are very rare cases, and each will be treated in an individualized way.

In general ectopic pregnancies are not considered viable. They are clearly life threatening to the mother. An ectopic pregnancy that is not treated will frequently lead to severe bleeding and death of the mother. I say this based on history, however, as in this day and age ectopics are diagnosed nearly 100% of the time before that happens. Usually they are diagnosed before they rupture, but in some cases a patient will present to the ED with a ruptured ectopic, at which time they will get surgery to deal with it. Death from ectopic pregnancy would be a pretty unheard of event, assuming that the woman presents to medical care when she has symptoms. Ectopics usually hurt for days to weeks before they rupture, giving women time to come. Most women who present with ruptured ectopics tell stories of having pain for weeks that they ignored, or in some cases they presented but did not get a timely diagnosis of what was going on.

Thanks for the question!