Management of Threatened Abortion
The primary management for threatened abortion is supportive care with close monitoring, as most cases do not require specific medical intervention beyond reassurance and follow-up. 1
Definition and Clinical Presentation
Threatened abortion is characterized by vaginal bleeding and/or uterine cramping during early pregnancy while the cervix remains closed. This condition affects approximately 15-20% of clinically recognized pregnancies 2.
Initial Assessment
- Confirm intrauterine pregnancy with ultrasound
- Assess vital signs and quantify bleeding
- Evaluate for cervical dilation (should be closed in threatened abortion)
- Check Rh status
- Consider quantitative β-hCG if pregnancy viability is uncertain
Management Approach
Supportive Care
- Bed rest is not proven to prevent progression but may be recommended for heavy bleeding
- Hydration and pain management as needed
- Emotional support and counseling regarding prognosis
- Serial ultrasounds to monitor fetal viability
Rh Immunoglobulin Administration
- Administer 50 μg of anti-D immunoglobulin to Rh-negative women with threatened abortion 1
- While ACOG notes that there is "no evidence-based recommendation" and many physicians do not treat when there is a live embryo or fetus, British authorities suggest it may be prudent to administer anti-D immunoglobulin when there is "heavy" bleeding, associated abdominal pain, or when the event occurs near 12 weeks' gestation 1
Progesterone Therapy
- Progesterone is commonly used in threatened abortion, though evidence for its efficacy is mixed 2
- Studies show that intramuscular progesterone treatment for threatened abortion during early pregnancy does not increase the risk of pregnancy complications, preterm birth, or low birth weight newborns 3
Follow-up Care
- Schedule follow-up within 1-2 weeks to reassess pregnancy status
- Serial β-hCG measurements may be helpful if viability is uncertain
- Repeat ultrasound to confirm ongoing viability
Prognosis and Complications
Threatened abortion is associated with:
- Higher risk of complications in the second half of pregnancy requiring medical intervention and/or hospitalization
- Increased risk of preterm birth
- Higher likelihood of placental retention
- Greater chance of low birth weight (<2000g) 4
- Higher rates of hyperemesis gravidarum, gestational diabetes mellitus, and placenta previa 5
Important Considerations
- Approximately 50-60% of early pregnancy losses are due to chromosomal abnormalities 2
- Treatment to maintain pregnancy is reasonable only when the fetus is not seriously affected
- Patients who experience threatened abortion should be considered higher risk and receive careful obstetric and perinatal supervision throughout pregnancy 4
- Psychological support is essential as women are at increased risk for significant depression and anxiety for up to one year after spontaneous abortion 6
When to Consider Alternative Management
If threatened abortion progresses to inevitable or incomplete abortion:
- Expectant management for up to two weeks is often successful
- Surgical evacuation remains the treatment of choice for unstable patients
- Medical management with misoprostol may be appropriate in selected cases 6
Remember that threatened abortion represents a risk group requiring careful monitoring throughout pregnancy, even if the immediate symptoms resolve.