How to manage high fibrinogen levels in a pregnant patient?

Management of High Fibrinogen in Pregnancy

Critical Clarification: High vs. Low Fibrinogen

The question about "high fibrinogen" in pregnancy requires clarification, as elevated fibrinogen is a normal physiological response to pregnancy and does not typically require intervention. 1 Normal pregnancy causes total fibrinogen concentrations to increase progressively with advancing gestational age, returning to baseline after delivery. 1

Physiological Fibrinogen Changes in Normal Pregnancy

• Fibrinogen naturally increases throughout pregnancy as part of the normal hemostatic adaptation to pregnancy. 1
• Total fibrinogen concentrations rise with advancing gestational age without an increase in the percentage of high molecular weight fibrinogen. 1
• This physiological elevation is not pathological and does not indicate a need for treatment or intervention. 1

When Elevated Fibrinogen Requires Attention

Thrombotic Risk Assessment

If the concern is thrombotic risk in the context of elevated fibrinogen, management should focus on standard thromboprophylaxis protocols rather than lowering fibrinogen levels. 2

• In patients with dysfibrinogenemia type 3B (thrombotic-related variants), thromboprophylaxis should be started at the beginning of gestation after pregnancy confirmation. 2
• For other patients, thromboprophylaxis recommendations follow those for the general population, independent of fibrinogen levels. 2
• Low molecular weight heparin (LMWH) is the preferred agent when pharmacologic thromboprophylaxis is indicated. 2

Monitoring Approach

• Quarterly assessment of fibrinogen activity level (and fibrinogen antigen level if available) is recommended only in patients with known congenital fibrinogen disorders. 2
• In normal pregnancy with physiologically elevated fibrinogen, routine monitoring is not indicated. 1

Management Algorithm for Suspected Pathological Elevation

Step 1: Determine if Elevation is Pathological

• Confirm whether fibrinogen elevation exceeds normal pregnancy ranges
• Assess for underlying thrombotic disorders or dysfibrinogenemia
• Review personal and family history of thrombosis 2

Step 2: Risk Stratification

• Patients with dysfibrinogenemia type 3B require immediate thromboprophylaxis at pregnancy confirmation. 2
• Patients with additional thrombotic risk factors should receive standard thromboprophylaxis per general population guidelines. 2
• Systematic monitoring of fetal growth is suggested in dysfibrinogenemia type 3B. 2

Step 3: Delivery Planning

• For patients on thromboprophylaxis, maintain fibrinogen levels ≥1.5 g/L for neuraxial anesthesia. 2
• Scheduled delivery is preferred when thrombotic risk is elevated. 2

Step 4: Postpartum Management

• Thromboprophylaxis for 6 weeks postpartum is indicated in dysfibrinogenemia type 3B. 2
• For other patients, standard postpartum thromboprophylaxis guidelines apply. 2

Common Pitfalls to Avoid

• Do not attempt to lower physiologically elevated fibrinogen in normal pregnancy - this is a protective adaptation. 1
• Do not confuse normal pregnancy-related fibrinogen elevation with pathological hyperfibrinogenemia requiring intervention. 1
• Avoid over-anticoagulation in patients without clear thrombotic risk factors, as this increases bleeding risk during delivery. 2
• In patients requiring both fibrinogen replacement (for low levels) and thromboprophylaxis, adjust fibrinogen replacement frequency rather than dose to minimize thrombotic risk. 2