Presumed diagnosis of ectopic pregnancy.

OBJECTIVE: To evaluate the accuracy of the diagnosis of presumed ectopic pregnancy.
METHODS: This was a retrospective cohort analysis at a tertiary care medical center. The patient population was composed of 1) clinically stable pregnant women with human chorionic gonadotropin (hCG) above 2000 mIU/mL and no evidence of an intrauterine pregnancy by ultrasound, or 2) women with an abnormal rise or fall of serial hCG below 2000 mIU/mL. Outcome was determined by pathologic evidence of chorionic villi in the endometrial curettings (or fallopian tube), or complete resolution of hCG.
RESULTS: Overall, 38.4% (43/112) of the women were diagnosed with a miscarriage and 61.6% (69/112) were found to have an ectopic pregnancy. No significant difference was found in race, age, gravity, parity, hCG trends, or time to diagnosis between women with ectopic pregnancies and those with miscarriages. Patients were more likely to be diagnosed with an ectopic pregnancy if the initial hCG value was below the discriminatory zone (relative risk 2.44; 95% confidence interval 1.07, 5.52). Ultrasound correlated well with the final diagnosis (P =.001) but was not definitive.
CONCLUSION: In an effort to save time, avoid dilation and curettage (D&C), and treat with methotrexate, the presence of an ectopic pregnancy is often presumed. The presumed diagnosis of ectopic pregnancy is inaccurate in almost 40% of cases. A D&C is necessary to differentiate an ectopic pregnancy from a miscarriage before a woman is presumptively treated with methotrexate.