When to Stop Duphaston in Threatened Abortion
Duphaston (dydrogesterone) should be continued until 1 week after vaginal bleeding has stopped in threatened abortion, with treatment typically extending through the first trimester (up to 12 completed weeks of gestation), whichever timepoint is longer.
Evidence-Based Treatment Duration
The research evidence consistently supports a specific discontinuation protocol for dydrogesterone in threatened miscarriage:
- Primary endpoint: Continue until 1 week after bleeding cessation 1, 2
- Alternative endpoint: Continue until 12 completed weeks of gestation 3
- Clinical rule: Use whichever timepoint is longer
This approach is based on multiple randomized controlled trials demonstrating that dydrogesterone reduces miscarriage rates when used with this protocol. In the Malaysian study, treatment with dydrogesterone 40 mg stat followed by 10 mg twice daily resulted in an 87.5% success rate (pregnancy continuing beyond 20 weeks) compared to 71.6% in controls 2. A similar study showed miscarriage rates of 17.5% with dydrogesterone versus 25% without treatment 1.
Dosing Protocol
Standard regimen:
- Loading dose: 40 mg orally as a single dose
- Maintenance: 10 mg twice daily (20 mg/day total)
- Continue as outlined above
Important Clinical Considerations
When bleeding stops early (before 12 weeks): Continue dydrogesterone for an additional 7 days after bleeding cessation, but do not stop before reaching 12 completed weeks of gestation.
When bleeding persists: Continue treatment through 12 weeks even if spotting persists, provided the pregnancy remains viable on ultrasound.
Safety profile: The evidence shows no increased risk of congenital abnormalities or adverse pregnancy outcomes with first-trimester dydrogesterone use 4. A meta-analysis of six randomized controlled trials confirmed no causal association between fetal abnormalities and first-trimester dydrogesterone (RR 0.96; 95% CI 0.57,1.62) 4.
Common Pitfalls to Avoid
- Stopping too early: Do not discontinue immediately when bleeding stops—wait the full additional week
- Stopping before 12 weeks: Even if bleeding resolves at 8 weeks, continue until at least 12 completed weeks
- Abrupt discontinuation: Gradual tapering is not specifically required based on available evidence, but ensure the full treatment course is completed
Monitoring During Treatment
While on dydrogesterone:
- Monitor for continued bleeding or new symptoms
- Confirm fetal viability with ultrasound as clinically indicated
- Assess for adverse effects (though incidence is low at 17.44% in one large study) 5
Note: Recent evidence from a 2024 Thai study showed no significant benefit of dydrogesterone over placebo 6, but this single study contradicts multiple earlier positive trials. The weight of evidence, including larger studies and real-world data from China showing widespread use 7, supports the continued use of dydrogesterone with the discontinuation protocol outlined above.