http://www.ajronline.org/cgi/content/full/176/3/607
Isabelle Trop and Deborah Levine

1 Radiology Department, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215.
Received April 3, 2000; accepted after revision August 4, 2000. Presented at the annual meeting of the American Roentgen Ray Society, Washington, DC, May 2000.

Vaginal bleeding is the most frequent indication for first-trimester sonography. In the presence of a live embryo, the most frequently encountered sonographic finding is a subchorionic hematoma. Bleeding in the second and third trimesters is less common. Bleeding restricted by the placenta, the amniotic or chorionic membranes, or both has characteristic sonographic features that are important to recognize because the prognosis varies with location. Bleeding within the fetus is uncommon. This pictorial essay presents the varied sonographic and MR imaging manifestations of bleeding throughout pregnancy