Diagnosis of early embryonic demise by endovaginal sonography.

Abstract

To determine the embryonic size at which cardiac activity is always seen in a normal early pregnancy, 398 endovaginal sonograms were evaluated in which the gestational sac contained a yolk sac and/or embryo of less than or equal to 12 mm in crown-rump length (CRL). In the 99 sonograms in which there was a yolk sac but no identifiable embryo, cardiac activity was absent in 75; 58 of these pregnancies progressed normally. Of the 299 sonograms where there was an identifiable embryo with CRL less than or equal to 12 mm, cardiac activity was absent in 31; 29 of these were proven to be failed pregnancies. In two cases the pregnancy progressed normally; the CRL was 2 mm in one case and 4 mm in the other. We conclude that once an embryo is seen by endovaginal sonography, the absence of cardiac activity usually indicates embryonic demise. However, when cardiac activity is absent, one should refrain from definitively diagnosing embryonic demise, based on a single sonogram, if the CRL is less than 5 mm.

The Expanded Amnion Sign

“…2,3,5,6,8 More recent studies have suggested that 3 mm, not 5 mm, should be the new cutoff 4,7 for diagnosis of death if ECA is not seen. Yet another study went to the opposite extreme and recommended using a CRL of 10 mm as the cutoff before diagnosing embryonic death.…”

“…[1][2][3][4][5][6][7][8] This is because pregnancy failure often can be confirmed with a single examination performed in less than 30 minutes. As noted above, the literature supports that a variety of sonographic features unambiguously confirm early pregnancy failure.…”

“…This is because there are literature references to the sonographic detection of early embryos before the onset of cardiac contractility. [2][3][4][5][6] Therefore, it is possible that tiny embryos without visible heartbeats are actually alive, but their heart has simply not yet begun to beat. Thus, repeated sonograms are commonly recommended when tiny embryos without heartbeats are identified.…”

Imaging in gynecology

“…The sensitivity and specificity with regard to failed early pregnancy of various ultrasound findings that have been suggested to be diagnostic of non-viability are shown in Table 2 [10][11][12][13][14][15]. The sensitivity and specificity will depend on the skill of the ultrasound examiner, the quality of the ultrasound equipment and any presence of technical problems, e.g., large uterine fibromas obscuring the view of the uterine cavity.…”

SOGC Clinical Practice Guidelines: Ultrasound Evaluation of First Trimester Pregnancy Complications

“…7 Transvaginal sonographic diagnosis of a blighted ovum is certain when the mean gestational sac diameter exceeds 8 mm without a yolk sac or when the mean gestational sac diameter exceeds 16 mm without an embryo. Transabdominally, a gestational sac greater than 20 mm without a yolk sac or 25 mm without an embryo is diagnostic of a blighted ovum.…”