Laparoscopy Laparoscopy is the gold standard for the diagnosis of ectopic pregnancy. The fallopian tubes are easily visualized and evaluated, but the diagnosis of ectopic pregnancy is missed in 3% to 4% of patients who have very small ectopic gestations. The ectopic gestation is seen distorting the normal tubal architecture. With earlier diagnosis, the possibility increases that a small ectopic pregnancy may not be visualized. Pelvic adhesions or previous tubal damage may compromise assessment of the tube. False-positive results occur when tubal dilation or discoloration is misinterpreted as an ectopic pregnancy, in which case the tube can be incised unnecessarily and damaged.
Diagnostic Algorithm The presenting symptoms and physical findings of patients with unruptured ectopic pregnancies are similar to those of patients with normal intrauterine pregnancies (35). History, risk-factor assessment, and physical examination are the initial steps in the management of suspected ectopic pregnancy. Patients in a hemodynamically unstable condition should undergo immediate surgical intervention. Patients with a stable, relatively asymptomatic condition may be assessed as outpatients.
If the diagnosis of ectopic pregnancy can be confirmed without laparoscopy, several potential benefits result. First, both the anesthetic and surgical risks of laparoscopy are avoided; second, medical therapy becomes a treatment option. Because many ectopic pregnancies occur in histologically normal tubes, resolution without surgery may spare the tube from additional trauma and improve subsequent fertility. An algorithm for the diagnosis of ectopic pregnancy without laparoscopy proved to be 100% accurate in a randomized clinical trial (172,173) (Fig. 20.5). This screening algorithm shows the combined use of history and physical examination, serial hCG levels, serum progesterone levels, vaginal ultrasonography, and dilation and curettage. When hCG levels and transvaginal ultrasonography are available in a timely fashion, serum progesterone screening is not required. Serial hCG levels are used to assess pregnancy viability, correlated with transvaginal ultrasonography findings, and measured serially after a suction curettage. For patients in a stable condition, a treatment decision is never based on a single hCG level. After the initial evaluation, the patient is seen again at 24 to 48 hours for a repeat hCG level. At this time, transvaginal ultrasonography often is repeated so the findings can be correlated with the two hCG levels.
In this algorithm, transvaginal ultrasonography is used as follows: 1. The identification of an intrauterine gestational sac or pregnancy effectively excludes the presence of an extrauterine pregnancy. If the patient has a rising hCG level of more than 2,000 mIU/mL, and no intrauterine gestational sac is