various normal changes of haematology in a pregnant woman

1. PHYSIOLOGICAL
HAEMATOLOGICAL
CHANGES IN
PREGNANCY
-Akshay.b.k

2. BLOOD VOLUME :
• During pregnancy there is increased vascularity of
uterus with the interposition of utero placental
circulation, leading to increased circulatory demand.
• Therefore there is progressive and inconsistent rise in
blood volume.
• It starts to increase by about 6th week of pregnancy to
about 40-50% (5500ml) above the non-pregnant level
at around 30-32 weeks.

3. PLASMA VOLUME :
• It starts to increase by 6 weeks and plateaus
at 30 weeks of gestation.
• Total plasma volume increases to the extent of
1.25lts( i.e. from 2500ml to 3750ml).
• The increase is greater in multigravida, in multiple
pregnancy, with large baby.

4. RBC & HAEMOGLOBIN :
• The RBC mass is increased to the extent of 20-30%
(i.e. 350ml).
• The increase is regulated by the increased demand of
O2 transport during pregnancy.
• RBC mass begins to increase by 10 weeks and
continues till term.
• Iron supplementation increases it by 30%.
• This disproportionate increase in plasma & RBC
volume produces haemodilution (i.e fall in PCV).

5. LEUCOCYTES &
IMMUNE SYSTEM:
• Neutrophilic leucocytosis occurs to the extent of
10 -15000/cu.mm and even to 20000/cu.mm during
labour.
• Increase is due to rise in oestrogen and cortisol levels.
• Major change in immune system is modulation away
from cell-mediated immune response towards
increased humoral and innate immunity.

6. TOTAL PROTEIN & BLOOD COAGULATION
FACTORS:
• Total plasma protein increases from normal 180gm to
230gm at term.
• Due to haemodilution plasma protein conc falls,
leading to decrease in viscosity of blood.
• A:G OF 1.7:1 is diminished to 1:1
• Pregnancy is a hypercoagulable state ,fibrinogen level
raises from 200-400mg/dl to 300-600mg/dl.
• ESR is increased (4 fold).
• Increased activity of clotting factors I,VII,VIII,IX,X.

7. Conclusion ( principal blood changes
in pregnancy ) :
parameters NON-PREGNANT PREGNANCY(ter
m)
CHANGE
BLOOD VOL (ml) 4000 5500 1500
PLASMA VOL (ml) 2500 3750 1250
RBC VOL (ml) 1400 1750 350
TOTAL Hb (gm) 475 560 85
TOTAL PROTEIN
(gm)
180 230 50
PLASMA PROTEIN
(gm/100ml)
7 6
FIBRINOGEN-mg% 200-400 300-600 +50%
ESR (mm/hr) 10 40 4 fold