What is the management for a threatened miscarriage?

Management of Threatened Miscarriage

The management of threatened miscarriage should focus on supportive care, as there is insufficient evidence to recommend bed rest or routine progesterone therapy, while ensuring appropriate monitoring and Rh immunoprophylaxis when indicated.

Definition and Diagnosis

Threatened miscarriage is characterized by vaginal bleeding with or without abdominal cramps during the first half of pregnancy, occurring in approximately 20% of recognized pregnancies 1. Key diagnostic criteria include:

• Vaginal bleeding in early pregnancy
• Closed cervical os
• Viable intrauterine pregnancy confirmed by ultrasound
• Presence of fetal cardiac activity

Initial Assessment

Clinical Evaluation

• Quantify bleeding severity and duration
• Assess for abdominal/pelvic pain
• Determine maternal vital signs
• Check for cervical dilation (closed in threatened miscarriage)

Laboratory Tests

• Complete blood count to assess hemoglobin level
• Blood type and Rh status
• Quantitative β-hCG levels (serial measurements if needed)

Imaging

• Transvaginal ultrasound to:
  • Confirm intrauterine pregnancy
  • Verify fetal cardiac activity
  • Assess gestational age
  • Rule out ectopic pregnancy

Management Protocol

1. Supportive Care

• Patient education and reassurance
• Avoid unnecessary interventions
• Regular follow-up to monitor pregnancy progression

2. Activity Recommendations

• Bed rest is NOT recommended as there is insufficient evidence that it prevents miscarriage 2
• The Cochrane review found no statistically significant difference in miscarriage rates between women prescribed bed rest versus no bed rest (RR 1.54,95% CI 0.92 to 2.58) 2
• Encourage normal activities as tolerated

3. Pharmacological Interventions

• Progesterone therapy: While some studies suggest progesterone or dydrogesterone may reduce miscarriage rates, there is insufficient high-quality evidence to recommend routine use 1, 3
• A randomized controlled trial investigating dydrogesterone (40mg loading dose followed by 10mg three times daily) is ongoing to better evaluate its efficacy 3

4. Rh Immunoprophylaxis

• Anti-D immunoglobulin (50μg) should be administered to Rh-negative women with threatened miscarriage, especially when associated with heavy bleeding or abdominal pain, or when near 12 weeks gestation 4
• This is important as fetomaternal hemorrhage can occur in 48% of threatened abortion cases 4

5. Follow-up Care

• Schedule follow-up ultrasound in 1-2 weeks to reassess fetal viability
• Monitor for resolution of bleeding
• Assess for signs of complete, incomplete, or missed miscarriage

Risk Factors and Prognosis

Factors associated with increased risk of progression to complete miscarriage include:

• Advanced maternal age (>35 years)
• Previous history of miscarriage
• Heavy bleeding
• Low serum progesterone or hCG levels
• Empty gestational sac >15-17mm in diameter 1
• Early gestational age at presentation

Psychological Support

Psychological consequences of threatened miscarriage and actual miscarriage can be significant, including:

• Increased risk of anxiety and depression
• Post-traumatic stress disorder
• Effects may last up to 12 months 5, 6

Appropriate counseling and psychological support should be offered to all women experiencing threatened miscarriage.

Special Considerations

Recurrent Miscarriage

• Women with history of recurrent pregnancy loss require more intensive monitoring
• These women may benefit from specialized care in high-risk pregnancy clinics 5
• Consider thrombophilia screening and other investigations for recurrent pregnancy loss

Venous Thromboembolism Risk

• Pregnancy itself increases VTE risk, though early pregnancy loss carries lower risk than later pregnancy
• The incidence of VTE within 6 weeks after early pregnancy termination is approximately 10 per 100,000 women 4
• Consider thromboprophylaxis in women with additional risk factors according to risk assessment models

When to Refer/Escalate Care

• Heavy bleeding requiring transfusion
• Signs of infection
• Hemodynamic instability
• Suspected ectopic pregnancy
• History of recurrent pregnancy loss