It has been nine days since the spontaneous abortion, and bleeding is still present. For the follow-up ultrasound examination, should I undergo an abdominal ultrasound or a transvaginal ultrasound?

It has been nine days since your spontaneous abortion, and you are still experiencing vaginal bleeding. An abdominal color Doppler ultrasound is recommended for follow-up evaluation, as it can accurately assess whether there is retained tissue within the uterine cavity and evaluate the extent of uterine recovery.

Spontaneous abortion refers to pregnancy loss occurring before 20 weeks’ gestation, commonly caused by embryonic developmental abnormalities, maternal physical exhaustion, or luteal phase insufficiency. Typical symptoms include abdominal pain and vaginal bleeding. Prolonged vaginal bleeding following spontaneous abortion may adversely affect overall health and necessitates prompt evaluation at a reputable hospital’s obstetrics and gynecology department. Abdominal B-mode ultrasound or color Doppler ultrasound is advised; Doppler imaging enables precise assessment of uterine morphology, degree of uterine involution, and presence of intrauterine retained tissue. If only minimal embryonic tissue remains in the uterine cavity, pharmacological management—such as Yimucao granules (Leonurus heterophyllus granules) and metronidazole tablets—may be prescribed under physician guidance. For larger amounts of retained tissue, uterine curettage may be required.

Transvaginal ultrasound is generally not recommended following spontaneous abortion, as incomplete or improper anti-infective measures during the procedure—or inappropriate technique—may irritate the reproductive tract or endometrial cavity and increase the risk of infection.