Transvaginal Doppler sonography for detecting ectopic pregnancy: is it really necessary

In this prospective study we compared transvaginal duplex Doppler ultrasound with two-dimensional imaging for the diagnosis or exclusion of ectopic pregnancies. The study group comprised 76 stable patients with serum beta-human chorionic gonadotropin (hCG) levels > 100 mIU/ml in whom ectopic pregnancy was clinically suspected. Ectopic pregnancies were verified in 42 patients (60%), intrauterine pregnancies (normal and abnormal) in 19 (27%), and possible complete abortions, either intrauterine or extrauterine, in 9 patients (13%). Based on 2-D imaging alone, the appearance of an adnexal mass separated from the ovaries, and a lack of clear intrauterine gestational sac indicated ectopic pregnancy with a sensitivity of 95%. Intrauterine sac-like structures and absence of adnexal masses excluded ectopic pregnancies with a specificity of 89%. High velocity systolic flow, and low impedance diastolic flow which characterizes trophoblastic tissue when detected outside the uterus, had a sensitivity of 48%, while the presence of trophoblastic signals in the uterus or their absence outside the uterus excluded ectopic pregnancies with a specificity of 89%. The positive predictive values were 91% for Doppler and 95% for 2-D imaging, while the negative predictive values were 89% for imaging alone and 44% for Doppler. These data suggest that transvaginal Doppler ultrasound has significant lower sensitivity and negative predictive value and does not provide more useful diagnostic information than 2-D imaging alone for stable patients with suspected ectopic pregnancies.