Dydrogesterone for Threatened Abortion
Dydrogesterone is not recommended for routine use in threatened abortion, as current guidelines do not support progestogen therapy for this indication, and the most recent high-quality randomized controlled trial found no benefit in preventing miscarriage.
Guideline-Based Management of Threatened Abortion
The standard management of threatened abortion focuses on diagnostic confirmation and supportive care, not hormonal intervention:
- Transvaginal ultrasonography is the diagnostic method of choice to confirm fetal viability and detect subchorionic hematoma 1
- Serial ultrasound examinations should be performed to assess fetal growth and development 1
- No evidence-based recommendation exists for progestogen administration in threatened abortion with a viable fetus, and many physicians do not treat when there is a live embryo or fetus 1
Critical Evidence Analysis
The evidence for dydrogesterone shows conflicting results, with the most recent and highest quality study being negative:
Most Recent Evidence (2024)
- A randomized, double-blind, placebo-controlled trial found no benefit: The continuing pregnancy rate beyond 20 weeks was 90.0% with dydrogesterone versus 86.0% with placebo (p = 0.538), showing no statistically significant difference 2
- This 2024 study used appropriate dosing (20 mg/day) and had rigorous methodology with 100 participants 2
Earlier Positive Studies (Lower Quality)
- A 2009 Malaysian open-label study showed higher success rates (87.5% vs 71.6%, p<0.05), but this was not blinded and therefore subject to bias 3
- A 2005 study showed benefit in recurrent abortion (13.4% vs 29% miscarriage rate), but this is a different clinical scenario than threatened abortion 4
Key Clinical Distinctions
Threatened abortion versus recurrent abortion are different entities:
- Threatened abortion is defined as vaginal bleeding with closed cervix and viable fetus 5
- The evidence for dydrogesterone in recurrent abortion (history of multiple prior losses) is separate from its use in acute threatened abortion 4
- Guidelines specifically address threatened abortion without recommending progestogen therapy 1
Essential Management Protocol
When managing threatened abortion, focus on:
- Confirm viability with transvaginal ultrasound immediately 1
- Rule out ectopic pregnancy as part of the diagnostic workup 1
- Assess Rh status: Administer 50 μg anti-D immunoglobulin to Rh-negative women if there is documented first-trimester loss, though administration is controversial in threatened abortion with viable fetus 1, 6
- Provide serial monitoring rather than hormonal intervention 1
Common Pitfalls to Avoid
- Do not routinely prescribe dydrogesterone based on older, non-blinded studies when the most recent rigorous trial shows no benefit 2
- Do not confuse threatened abortion with recurrent pregnancy loss, as these require different management approaches 5, 4
- Do not delay appropriate diagnostic workup (ultrasound, ectopic pregnancy exclusion) while initiating empiric hormonal therapy 1