What is the initial management for a threatened abortion?

Initial Management of Threatened Abortion

The initial management of threatened abortion should include bed rest, uterine sedatives, folic acid supplementation, and hormonal treatment to improve pregnancy outcomes. 1

Definition and Clinical Presentation

• Threatened abortion is characterized by vaginal bleeding with or without abdominal cramping during the first half of pregnancy while the cervical os remains closed and the fetus remains viable 2, 3
• It is the most common complication in early pregnancy, with most pregnancies continuing to term with or without treatment 1
• Spontaneous abortion occurs in less than 30% of women presenting with threatened abortion 1

Diagnostic Approach

• Transvaginal ultrasonography is the diagnostic method of choice to:
  • Confirm fetal viability (presence of cardiac activity) 2, 4
  • Detect the presence of subchorionic hematoma, which appears as an extrachorionic crescentic anechoic or complex collection 4
  • Rule out other complications such as ectopic pregnancy 5
• Serial β-hCG measurements may be necessary if ultrasound findings are inconclusive 2

Management Protocol

Immediate Interventions

• Complete bed rest until 48 hours after cessation of bleeding 1
• Uterine sedatives to reduce cramping 1
• Folic acid supplementation 1
• Hormonal treatment (progesterone) until 28 weeks of gestation 1
  • Progesterone is the most important hormone for the maintenance of early pregnancy 3

Rh Status Evaluation

• Administer 50 μg of anti-D immunoglobulin to Rh-negative women in all cases of documented first-trimester loss of established pregnancy 5
• For threatened abortion with viable fetus, anti-D immunoglobulin administration is controversial:
  • British authorities suggest it may be unnecessary before 12 weeks' gestation unless there is "heavy" bleeding, associated abdominal pain, or when the event occurs near 12 weeks' gestation 5
  • ACOG states there is no evidence-based recommendation, and many physicians do not treat when there is a live embryo or fetus 5

Prognostic Factors

• Presence of fetal cardiac activity is the most important positive prognostic factor 4
• Subchorionic hematoma affects prognosis:
  • In the absence of subchorionic bleeding, 100% of pregnancies with fetal cardiac activity progressed to term 4
  • With subchorionic bleeding present, positive outcome was reduced to 80% 4
  • Spontaneous abortion was more common with subchorionic hematoma size greater than 20 cm² 1

Potential Complications

• Threatened abortion is associated with increased risk of:
  • Antepartum hemorrhage (7.5%) 1, 6
  • Preterm labor and delivery 1, 6
  • Intrauterine growth restriction (13.2%) 1, 6
  • Preterm premature rupture of membranes (5.66%) 1
  • Intrauterine fetal death (5.66%) 1
  • Retention of placenta 6

Follow-up Care

• Regular prenatal visits with close monitoring throughout pregnancy 6
• Serial ultrasound examinations to assess fetal growth and development 2
• Psychological support for the patient and partner, as women are at increased risk for significant depression and anxiety for up to one year after spontaneous abortion 7

When to Consider Alternative Management

• If bleeding becomes heavy or cervical os dilates, the diagnosis changes to inevitable abortion 2
• If fetal cardiac activity is absent at or beyond 9 weeks, fetal death should be confirmed and appropriate management initiated 4
• If signs of infection develop, treatment for septic abortion should be initiated 2