
Gestational Sac The gestational sac is the earliest sonographic finding in pregnancy. The gestational sac appears as an echogenic (bright echoes) ring surrounding a sonolucent (clear) center. The gestational sac does not correspond to specific anatomic structures, but is an ultrasonic finding characteristic of early pregnancy. Ectopic pregnancies can also have a gestational sac identified with ultrasound, even though the pregnancy is not within the endometrial cavity. The gestational sac first appears... more



