Agents injected into the amniotic sac at laparoscopy included prostaglandin F2a, hyperosmolar glucose, and methotrexate (216–218). This method has the obvious disadvantage of requiring laparoscopy, but it can be used if laparoscopy is performed for diagnosis. Other agents reported for the treatment of ectopic pregnancy include RU-486 and anti-hCG antibody (219,220).
Types of Ectopic Pregnancy
Spontaneous Resolution Some ectopic pregnancies resolve by resorption or by tubal abortion, obviating the need for medical or surgical therapy (221–225). The proportion of ectopic pregnancies that resolve spontaneously and the reason they do so while others do not are unknown. There are no specific criteria for patient selection that predict successful outcome after spontaneous resolution. A falling hCG level is the most common indicator used, but tubal rupture can occur even with falling hCG levels. Patients with low initial levels of β-hCG are generally the best candidates for expectant management, and there is a reported 88% success rate of spontaneous remission with an initial β-hCG level less than 200 mU/mL (226). These patients should be followed with serial β-hCG levels and active management initiated if these levels plateau or rise or the patient develops abdominal pain or signs of tubal rupture (190).
Persistent ectopic pregnancy occurs when a patient underwent conservative surgery (e.g., salpingostomy, fimbrial expression) and viable trophoblastic tissue remains. Histologically, there is no identifiable embryo, the implantation usually is medial to the previous tubal incision, and residual chorionic villi are confined to the tubal muscularis. Peritoneal trophoblastic tissue implants may be responsible for persistence (182,183,227–230).
The incidence of persistent ectopic pregnancy increased with the increased use of surgery that conserves the tubes. Persistence is diagnosed when the β-hCG levels plateau after conservative surgery. Risk factors for persistent ectopic pregnancy are based on the type of surgical procedure, the initial β-hCG level, the duration of amenorrhea, and the size of the ectopic pregnancy. Patients treated with laparoscopic salpingostomy have a higher rate of persistent ectopic pregnancies compared to those treated with salpingostomy at the time of a laparotomy, with an incidence of persistence after laparoscopic linear salpingostomy ranging from 4% to 15% (49,177). Other risk factors for persistent ectopic pregnancies include very early gestations (amenorrhea less than 7 weeks’ duration), ectopic pregnancies less than 2 cm, and those with high starting β-hCG levels (183,185,229).
Persistent ectopic pregnancy can be treated surgically or medically; surgical therapy consists of either repeat salpingostomy or, more commonly, salpingectomy. Methotrexate offers an alternative to patients who are hemodynamically stable at the time of diagnosis. Methotrexate may be the treatment of choice because the persistent trophoblastic tissue may not be confined to the tube and, therefore, not readily identifiable during repeat surgical exploration (231–233).