Ultrasonographic diagnosis of incompetent cervix. A case report.

The ultrasonographic findings of an incompetent cervix, the protrusion of the lower pole of the fetal membranes through the dilated internal os, may precede physical changes in the cervix. The symptoms at that time may be nonspecific. As this case report indicates, we believe that action--either close observation, conservative treatment or surgical intervention--should follow the detection of this condition.