Diagnosis of acute and persistent ectopic pregnancy.

Abstract

The diagnosis of ectopic pregnancy has undergone a major evolution in the past two decades. The introduction of sensitive β subunit human chorionic gonadotropin (β-hCG) assays and high resolution transvaginal sonography has enabled precise and early diagnosis of ectopic pregnancy before the development of critical signs and symptoms. Historically, clinicians managed ectopic pregnancy by excision via laparotomy. The suspicion for ectopic pregnancy resulting from the diagnostic work-up had to be strong enough to justify performing a major operation. The desire for conservative management of ectopic pregnancy and oviduct preservation made the diagnosis of unruptured gestational mass essential. The introduction of laparoscopy gave the clinician a powerful tool that enabled the making of an accurate diagnosis without a laparotomy skin incision. Later, the development of operative laparoscopy added a treatment ability to this diagnostic procedure. With the recent advent of medical treatment for ectopic pregnancy, an accurate and early diagnosis of ectopic pregnancy has become even more important. Although a surgical approach gives the clinician an opportunity to confirm the diagnosis, the medical therapy does not provide this verification, and, therefore, the diagnostic process must be thorough. In the past, many patients who were taken to the operating room with a diagnosis of presumptive ectopic pregnancy were found to have other benign conditions mimicking an ectopic pregnancy and frequently not requiring surgical treatment.1 A modern and more precise diagnostic process may limit or even eliminate such unnecessary surgical procedures. Thanks to a more reliable and earlier diagnosis of ectopic pregnancy, the initial presentation of a woman with this condition has changed during the recent years. Fewer patients develop acute abdomen and hypovolemia resulting from a ruptured and acutely bleeding ectopic implantation site. More prompt diagnosis and earlier intervention has led to a dramatic decrease in mortality from ectopic pregnancy. The population of women at high risk for developing ectopic pregnancy can be identified and prospectively screened for the location of implantation site early after conception.2 The advancement in the field of assisted reproductive technology (ART) has brought some new challenges to the diagnosis of ectopic pregnancy. Multiple implantations resulting from the transferring of multiple embryos obtained through fertilization in vitro may lead to more frequent heterotopic pregnancies (1% of all pregnancies resulting from in vitro fertilization), which are rare in spontaneous, unstimulated reproductive cycles (1:5,000 pregnancies). The natural history of ectopic pregnancy may vary. In some cases of trophoblast in regression, an early ectopic pregnancy may be in the process of spontaneous resolution, and no intervention is necessary. Other women who may be asymptomatic and clinically stable with no signs of intra-abdominal bleeding and no apparent adnexal mass may experience a sudden rupture of a small gestational extra-uterine mass and quickly develop hypovolemic shock. These different dynamics in the development of an ectopic pregnancy may confuse the clinician, who needs to remain cautious and critical during the diagnostic process. Conservative surgical management of ectopic pregnancy as well as medical therapy may not eradicate the trophoblastic tissue entirely. The remaining trophoblast may preserve its viability and continue to grow, leading to persistent ectopic pregnancy. Although the incidence of persistent ectopic pregnancy is low, ranging from 2-20% of conservatively treated women, it may result in sudden hemorrhage and tubal rupture in 24% of the cases.3