Ectopic pregnancy: transvaginal color Doppler of trophoblastic flow in questionable adnexa.

The purpose of this study was to see if color flow Doppler measurements could aid in the positive diagnosis of ectopic pregnancy when no gestational sac can be seen in the adnexa. We examined 148 women with abdominal pain and suspected ectopic pregnancy by abdominal ultrasonography, followed by vaginal ultrasonography and color Doppler when the diagnosis was still uncertain. Seventy-three patients proved to have ectopic pregnancies. Color flow with low resistance and high velocity vascular signals were observed in complex adnexal masses and in some of the corpora lutea. The resistance index for ectopic trophoblast was 0.36 +/- 0.02 SD. Color Doppler had both positive and negative discrimination of adnexal masses (P = 10(-15). The resistance index for the corpora lutea was 0.48 +/- 0.04. A cutoff value of 0.40 or less is proposed as a diagnostic index for suspected trophoblast in the adnexa. In nine cases of ectopic pregnancy, no color flow was noted. In these women, the beta-human chorionic gonadotropin level was less than 1000 mIU/ml. The clinical operative suspicion in these cases was tubal abortion. Sensitivity and specificity were 88% and 97%, respectively, in this highly selective series. Positive and negative predictive values were 97% and 89%. Color Doppler appears to be useful for the positive diagnosis of ectopic pregnancy with ultrasonography when no adnexal gestational sac is observed. Prospective randomized trials will determine the ultimate clinical value of these findings.