Haemostasis in normal pregnancy

Area of Science:

• Obstetrics and Gynecology
• Hematology
• Physiology

Background:

• Pregnancy involves complex physiological adaptations, including significant alterations in the haemostatic system.
• Understanding these changes is vital for managing potential complications such as thrombosis and hemorrhage.

Purpose of the Study:

• To systematically document changes in multiple haemostatic variables during and after pregnancy in 72 women.
• To investigate the dynamic alterations in coagulation factors, inhibitors, and fibrinolytic activity throughout gestation.

Main Methods:

• Prospective study involving 72 women.
• Measurement of a wide range of haemostatic variables, including coagulation factors (II, V, VII, X, fibrinogen), inhibitors (antithrombin III, alpha 1-antitrypsin, alpha 2 macroglobulin), and fibrinolytic markers (fibrin degradation products).
• Analysis of changes across different stages of pregnancy and postpartum.

Main Results:

• Marked increases observed in Factors VII, VIII:C, VIIIR:Ag, X, fibrinogen, and alpha 1-antitrypsin throughout pregnancy.
• Factors II and V, and alpha 2 macroglobulin initially increased but then declined; Antithrombin III levels slightly decreased.
• Significant reduction in fibrinolytic activity from 11-15 weeks, with rising fibrin degradation products from 21-25 weeks.

Conclusions:

• The observed rise in coagulation factors may result from increased synthesis or thrombin activation.
• Findings suggest a potential mild, localized intravascular coagulation in some women during pregnancy.
• These haemostatic shifts highlight the prothrombotic state often associated with normal pregnancy.