Incomplete Abortion
This clinical presentation—vaginal bleeding, pain, passage of tissue at home, and an open cervix on examination—is diagnostic of an incomplete abortion. 1
Clinical Classification
An incomplete abortion occurs when some, but not all, products of conception have been expelled from the uterus, with the cervical os remaining open. 1 The key distinguishing features in this case are:
- Passage of tissue vaginally confirms that expulsion has begun 2
- Open cervix on examination indicates the abortion process is ongoing and incomplete 1
- Continued bleeding and pain reflect retained products of conception still within the uterus 1
Differential Diagnosis of Spontaneous Abortion Types
To understand why this is specifically an incomplete abortion, consider the classification:
- Threatened abortion: Bleeding with a closed cervix and viable pregnancy 1
- Inevitable abortion: Bleeding with an open cervix but no tissue passage yet 1
- Incomplete abortion: Tissue passage with open cervix and continued bleeding (this patient) 1
- Complete abortion: All tissue passed, cervix closing, bleeding diminishing 1
- Missed abortion: Nonviable pregnancy retained in utero with closed cervix 1
Diagnostic Confirmation
Transvaginal ultrasound is the definitive imaging modality to confirm retained products of conception and assess the endometrial cavity. 3 Key findings include:
- Endometrial thickening or focal masses suggesting retained tissue 2
- Doppler flow within endometrial abnormalities strongly supports retained products of conception 2
- Assessment of cervical status from external to internal os 3
Transabdominal ultrasound alone is frequently inadequate for evaluating the lower uterine segment and endometrial cavity after tissue passage. 3
Management Approach
For incomplete abortion, treatment options include:
- Expectant management for up to two weeks, which is successful in most cases 1
- Medical management with misoprostol (80% success rate for evacuation) 1
- Surgical evacuation (suction curettage) remains the treatment of choice in hemodynamically unstable patients 1
If transvaginal ultrasound demonstrates retained products >15 mm or significant endometrial thickening, uterine evacuation should be considered to prevent delayed hemorrhage or infection. 3
Critical Pitfalls
- Do not confuse with inevitable abortion—the key difference is that inevitable abortion has an open cervix but no tissue passage yet, while incomplete abortion has documented tissue passage 1
- Do not rely solely on clinical examination; ultrasound confirmation of retained products guides definitive management 3
- Assess for signs of infection (septic abortion) including fever, foul discharge, or endometrial fluid collections on ultrasound 3