Can tranexamic acid (TXA) be used in cases of miscarriage?

Can TXA Be Used in Miscarriages?

Tranexamic acid is NOT recommended for routine use in miscarriage management based on current high-quality guidelines, which focus exclusively on postpartum hemorrhage (after delivery) rather than pregnancy loss. The available guideline evidence addresses TXA use only after birth, and the FDA label does not clarify whether TXA poses risks for miscarriage or adverse fetal outcomes 1.

Critical Context: What the Guidelines Actually Cover

The WHO guidelines specifically address TXA for postpartum hemorrhage (bleeding after delivery), not bleeding during miscarriage 2. This is a crucial distinction:

• Postpartum hemorrhage = bleeding after a baby is delivered (>500 mL vaginal delivery or >1000 mL cesarean) 3
• Miscarriage bleeding = bleeding during pregnancy loss, typically in first or second trimester

Limited Evidence for Miscarriage-Related Bleeding

Congenital Fibrinogen Disorders Only

The only guideline-level recommendation for TXA during pregnancy loss comes from a highly specialized scenario:

• For women with afibrinogenemia or severe hypofibrinogenemia (rare congenital bleeding disorders), TXA is recommended for 3 days during pregnancy loss management, combined with fibrinogen replacement targeting levels ≥1.5 g/L 4
• This represents an exceptional case where the bleeding risk from the underlying disorder justifies TXA use 2

Older Research Data (Low Quality)

One 2007 Russian study suggested TXA may help arrest bleeding in threatened abortion and miscarriage 5, but this:

• Predates modern guideline development
• Lacks the rigor of contemporary randomized trials
• Has not been incorporated into any major clinical guidelines

Why Guidelines Don't Support Routine Use in Miscarriage

Safety Concerns During Pregnancy

The FDA label explicitly states: "It is not known whether tranexamic acid use in pregnant women may cause a drug-associated risk of miscarriage or adverse maternal or fetal outcomes" 1

Key safety issues:

• TXA crosses the placenta with cord blood concentrations equal to maternal levels 1
• Two infant deaths with structural abnormalities occurred when TXA was used during conception or first trimester, though causality remains unclear 1
• 13 clinical studies documented fetal/neonatal functional issues (low Apgar scores, neonatal sepsis) and 9 studies noted growth alterations (low birth weight, preterm birth) with in-utero TXA exposure 1

Thromboembolic Risk

• TXA should be avoided in women with known thromboembolic events during pregnancy 2, 4
• Concomitant use with hormonal contraceptives increases thrombotic risk 1

When TXA IS Indicated in Obstetric Settings

Postpartum Hemorrhage (After Delivery)

TXA should be given as soon as possible within 3 hours of birth for PPH treatment 2, 4:

• Dose: 1g IV over 10 minutes, with possible second 1g dose if bleeding continues after 30 minutes 3, 4
• Efficacy decreases 10% for every 15-minute delay 2
• No benefit after 3 hours, and potentially harmful 2

Cesarean Section Prophylaxis (Controversial)

Recent high-quality evidence shows prophylactic TXA during cesarean results in little to no difference in estimated blood loss ≥1000 mL, though it may slightly reduce calculated blood loss 6. Given low PPH morbidity rates and uncertainty about serious adverse events, routine prophylactic use remains debatable 6.

Clinical Decision Algorithm for Obstetric Bleeding

If bleeding occurs DURING pregnancy (miscarriage):

• Do NOT use TXA routinely
• Exception: Women with documented congenital fibrinogen disorders (afibrinogenemia, severe hypofibrinogenemia) may receive TXA for 3 days with fibrinogen replacement 4
• Manage with standard miscarriage protocols (expectant, medical, or surgical management)

If bleeding occurs AFTER delivery (postpartum):

• Check for contraindications: history of thromboembolic events 2, 4
• Confirm timing: within 3 hours of birth 2, 4
• Administer 1g IV over 10 minutes immediately 3, 4
• Monitor for thrombotic complications 4

Critical Pitfalls to Avoid

Drug Administration Error (Fatal)

Never store TXA near anesthetic drugs - multiple deaths have occurred from inadvertent intrathecal administration instead of spinal anesthetic during cesarean delivery 7. This causes rapid-onset convulsions with 50% mortality 7. Store TXA separately from operating room anesthetic supplies with auxiliary warning labels 7.

Timing Error

Administering TXA beyond 3 hours after birth is potentially harmful and provides no benefit 2. The 3-hour window is absolute for postpartum use.