No abstract

The interstitial line sign is a useful diagnostic sign of interstitial ectopic pregnancy.

Four hundred eighty-six consecutive women who underwent endovaginal sonography when their fetuses were less than 10 weeks menstrual age (MA) were evaluated to establish the normal size and shape of the secondary yolk sac (YS) and to assess the value of YS measurement in predicting pregnancy outcome in the first trimester. A YS diameter more than two standard deviations (SDs) above the mean when compared with the mean gestational sac diameter allowed prediction of an abnormal pregnancy outcome with a sensitivity of 15.6%, a specificity of 97.4%, and a positive predictive value of 60.0%. A YS diameter more than two SDs below the mean allowed prediction of an abnormal outcome with a sensitivity of 15.6%, a specificity of 95.3%, and a positive predictive value of 44.4%. No pregnancy with a normal outcome had a YS diameter of greater than 5.6 mm at less than 10 weeks MA. In six patients, the YS diameter was greater than 5.6 mm. All six had an abnormal outcome. Of seven patients with abnormal YS shape at initial sonography, three had abnormal YS shape at follow-up examinations. All three had an abnormal outcome.

The mean diameter of the gestation sac and the presence or absence of a yolk sac or embryo and/or cardiac pulsations on endovaginal ultrasound (US) images were correlated with normal and abnormal outcomes of pregnancy. Sixty-two patients who were less than 10 weeks pregnant (menstrual age) underwent endovaginal US. In 59 patients with gestation sacs greater than or equal to 8 mm, the absence of a yolk sac predicted a nonviable pregnancy with a sensitivity of 67% and a specificity of 100%. In 35 patients with gestation sacs greater than or equal to 16 mm, the absence of an embryo predicted a nonviable pregnancy with a sensitivity of 50% and a specificity of 100%. When the absence of cardiac pulsations was added to the latter group of patients, the sensitivity was 100% and the specificity was 100%. The combination of these criteria (gestation sac size; demonstration of yolk sac, embryo and/or cardiac pulsations) enabled the early (less than 10 weeks menstrual age) diagnosis of a nonviable pregnancy with endovaginal US.

The authors reviewed the endovaginal ultrasonographic (US) findings for 96 patients with embryos with crown-rump lengths of less than 5.0 mm. Of the 71 patients with adequate follow-up, initial endovaginal US demonstrated cardiac activity in 46 embryos and no cardiac activity in 25. Initial endovaginal US failed to demonstrate cardiac activity in five of 40 normal embryos, three with crown-rump lengths of less than 2.0 mm and two, between 2.0 and 3.9 mm. Endovaginal US identified cardiac activity in all 12 normal embryos with crown-rump lengths of 4.0-4.9 mm. The presence of cardiac activity was associated with a 24% risk of spontaneous abortion. In embryos between 2.0 and 4.9 mm in crown-rump length, absent cardiac activity was associated with a 91% risk of abortion. All 17 patients with vaginal bleeding and embryos demonstrating no cardiac activity subsequently aborted. The embryonic yolk sac was absent in 35% of patients who subsequently aborted. Variation outside of the 95% confidence limits of the mean for crown-rump length compared with mean gestational sac diameter and yolk sac diameter was also helpful in predicting an abnormal outcome. Nonvisualization of cardiac activity at endovaginal US in embryos less than 4.0 mm in crown-rump length may be normal and warrants follow-up US examination.