Subchorionic bleeding in threatened abortion: sonographic findings and significance.

Fifty-six patients with clinical threatened abortion were evaluated by sonography. In six patients, fetal cardiac activity was absent at or beyond 9 weeks of gestation, and fetal death was confirmed in all six cases. In the other 50 patients, fetal cardiac activity was present at or beyond 9 weeks of gestation. In 10 (20%) of these 50 patients, subchorionic bleeding was present in various degrees, appearing sonographically as an extrachorionic crescentic anechoic or complex collection. The final outcome in the 50 patients with fetal cardiac activity was as follows: In the absence of subchorionic bleeding, 100% of the pregnancies progressed to term; in the presence of subchorionic bleeding the positive outcome was reduced to 80%. In addition to signs of fetal life on sonography, subchorionic bleeding is an important factor affecting the outcome of gestations in patients with clinical threatened abortion.