Determination of whether the viewed structure is the embryo is critical, as no other morphologically recognizable structures other than a heartbeat exist at this stage of development. The embryo must be scanned thoroughly for evidence of a heartbeat. Most recommendations call for 2 independent examiners to view the embryo, either concurrent with the ED visit or at follow-up. Most sonographers recommend repeating the scan within 3-7 days to determine whether the embryo is developing normally. Apply endovaginal ultrasound whenever possible to limit image distortion due to patient habitus or an overdistended bladder.
Pelvic ultrasound is a clinically useful tool in the evaluation of spontaneous abortion.
Transabdominal ultrasound of the pelvis provides an overall view of the pelvic structures. A full bladder is required as a sonographic window. An empty bladder is preferred. If tissue has been passed, advise the patient to bring the material to the hospital for evaluation. Pelvic ultrasonography may be useful in clinically classifying spontaneous abortion.