Medical management of ectopic pregnancy

Antonio Pardo.
17 September 2013.

In some cases, ultrasound examination of a suspected pregnancy reveals that the embryo has implanted in an abnormal location, such as the cervix or fallopian tube (most frequently). On other occasions, the implantation may be in the mesentery or another part of the abdominal cavity, which is difficult to detect on entrance with ultrasound.

All of these implantations are lethal in the short term deadline for the embryo, with the exception of a few very rare cases of mesenteric implantation, which have been carried to term and delivered by laparotomy, which also serves to repair the mesentery and remove the affected intestinal loops.

Very often, before the existence of ultrasound, the first symptom of ectopic pregnancy was a ruptured tube, with the subsequent onset of severe acute haemorrhage, which required urgent surgical treatment. The ruptured and bleeding tube was removed as a matter of urgency (salpinguectomy), taking with it the embryo, usually already dead by then.

The advent of ultrasonography made it possible to detect abnormal implantations before they led to tubal rupture and subsequent acute haemorrhage. The medical approach indicated in the early days of ultrasound was removal of the tube, which prevented subsequent haemorrhage.

When ultrasound began to be used systematically, some researchers were surprised by the high frequency of ectopic pregnancies compared to the pre-ultrasound era, and discovered that a large proportion of them resolve spontaneously: the implantation site does not have sufficient blood supply and the tissue is not adequate for the growth of the trophectoderm for the placenta to develop. This abnormality causes human chorionic gonadotrophin-β-hCG to reach only low levels, a circumstance that can help in the diagnosis. The result is that the embryo dies spontaneously due to lack of adequate nutrition and oxygenation, and its remains are reabsorbed by the maternal organism. For this reason, some authors proposed that, when faced with an ectopic implantation on ultrasound, finding , the best thing to do was to wait and not operate directly, as the spontaneous death of the embryo would make intervention unnecessary most of the time. It should be borne in mind that, in those years, surgery was always open and, therefore, quite aggressive in comparison with today's laparoscopic interventions.

Subsequently, less aggressive alternatives to salpinguectomy were discovered: salpingotomy and methotrexate employment . Salpingotomy consists of making a longitudinal incision in the tube and extruding the entire embryo sac (including the embryo, which dies if it is alive), so that there is no longer any danger of acute hemorrhage linked to its growth. Methotrexate, injected into the embryonic sac (as was done at the beginning) or systemically (usually one intramuscular dose, sometimes two if one is not enough), acts by slowing down the proliferation of the trophoblast, i.e. the growth of the embryonic tissues which infiltrate the maternal tissues to allow the nourishment of the embryo by generating the placenta; It thus stops the progress of the injury to the mother's tissues but, as a side effect, the embryo also dies due to lack of nutrition and oxygenation, and is reabsorbed by the maternal organism.

Currently, treatment with methotrexate is tried whenever possible, as it is not very harmful to the mother and does not leave sequelae; this treatment is not possible if there is an imminent threat of rupture of the tube, or some other circumstance that requires surgical treatment (salpingostomy or salpingectomy, depending on status).

Some have claimed that these treatments (both past and present) would be immoral because they destroy the life of the embryo, and would be ethically equivalent to internship abortion. This assertion comes from confusing the facts Materials with the decisions that are taken. Indeed, with all these treatments of the mother's problem, the embryo ends up dying (if it is not already dead or seriously affected by the abnormal status ); but in all the cases mentioned, the doctor's decision is to treat a health problem of the mother, caused by the proliferation of trophoblastic tissues in an inappropriate place. This is done by surgical removal of these tissues (salpingotomy or salpingectomy) or with drug treatment (methotrexate). As a tolerated effect, the fact that the child will die is always given, but this is not what is intended, decided and done: a problem of the mother is being treated; and this tolerated effect, given the seriousness of the condition being treated (it can be fatal for the mother if no action is taken), is ethically acceptable. This issue is even clearer if one takes into consideration that the child has no prospect of being able to live in any case, assuming that he or she is still alive at the time of treatment.

In any case, it should be borne in mind that the ethical correctness of these actions is not because the child is sentenced to death: this also happens when a foetus suffers from serious malformations, such as bilateral renal agenesis, anencephaly, severe pulmonary hypoplasia, etc., which will lead to death shortly after birth. In these cases, abortion has become common internship . However, although the latter internship is widespread, it has a radical difference with the treatment of ectopic pregnancy: abortion performed because of foetal malformations is not treating any health problems of the mother or the foetus. On the contrary, surgical or pharmacological intervention for ectopic pregnancy is, above all, treatment of a serious problem of the mother, and this is what makes it admissible: the decisive factor is not the additional circumstance that the child will die spontaneously.