Investigations for suspected retained products of conception

Retained products of conception is usually a clinical diagnosis based on bleeding patterns. The presentation varies and clinical judgment is required to determine if and when intervention is required. Input from an experienced practitioner may be needed.

If symptoms of retained products are present, and the individual does not have haemorrhage requiring emergency management, examine the cervix and remove any clots that are present.

Further investigations are not routinely required if all of the following are present:

• the serum hCG concentration dropped to below 20% of baseline
• the bleeding is light or only intermittently moderate
• there is no clinical suspicion of anaemia
• the individual is well.

Investigations are required if the bleeding is heavier than expected at any stage after the medical abortion. Check the full blood count and iron studies to assess the degree of blood loss and detect moderate to severe anaemia and guide management. Compare the results with baseline studies if available.

An ultrasound scan can be useful to assess the presence of retained products of conception, but a scan earlier than 3 weeks post misoprostol is unlikely to be helpful—blood clots are likely to be present and can interfere with interpretation. However, an ultrasound should not be delayed if a continuing pregnancy is suspected. Consistent guidelines for determining the significance of retained products (by volume and features, including vascularity), are lacking, and case-by-case interpretation is required, based on clinical features and ultrasound findings.

If the ultrasound scan shows significant retained products of conception, surgical evacuation may be indicated; refer for specialist assessment.

If the ultrasound scan does not show significant retained products of conception, bleeding is likely to resolve spontaneously. Support the individual to make an informed choice between expectant management or medical management, with the option of surgical evacuation as backup. Also manage any concurrent infection.