Haematological changes in pregnancy

Haematology

Plasma volume increases (45%) relatively more than RBC volume increase (20%)

Thus,

• [Hb] falls to 12-13g/L
• Haematocrit falls to 33-35%

Also,

• WBC count increases to 8 to 9 x 10^6/L
  * Due to increase in neutrophil and monocytes

NB:

According to [KB2:p6],

• Without iron supplementation
  --> RBC volume increase by 250mLs (18%)
• With iron supplementation
  --> RBC volume increase by 450mLs (30%)

Coagulation

Significant increase in plasma concentration of

• Factor 7,8,9,10
• Fibrinogen

Platelet concentration is unchanged or slightly decreased due to haemodilution

NB:

According to [AA4:p328],

• Factor II, V slightly increased
• Factor VII increase 10-fold
• Factor VIII increase 2-fold
• Factor IX and X increased
• Factor XII increase 30-40%
• Factor XI and XIII decreased
• Plasminogen inhibitor increased
• Plasminogen activator reduced
• Antithrombin IIIa decreased slightly

Plasma proteins

• Total circulating protein increase during pregnancy

But,

• Concentration of total protein and albumin decrease due to haemodilution

Other proteins

• Increase in total globulin
  * Increase in alpha and beta-globulin
  * Slight decrease in gamma-globulin
• Fibrinogen increases
  * From 300mg/dL to 450mg/dL at term
• Serum pseudocholinesterase activity
  * Reduced by 20-30% by the end of 1st trimester
  * Constant until term