(C) Decrease in fibrinogen levels # PHYSIOLOGICAL CHANGES ASSOCIATED WITH PREGNANCY:> Blood Volume increases progressively from 6-8 weeks gestation (pregnancy) and reaches a maximum at approximately 32-34 weeks with little change thereafter.> Renal plasma flow and glomerular filtration rate begin to increase progressively during the first trimester.> Increases in blood volume and cardiac output.> Elevations in plasma flow and glomerular filtration result in an elevation in creatinine clearance.> Blood urea and serum creatinine are reduced by 40%.> here is also an increase in filtered sodium, but tubular absorption is increased by an increase in aldosterone secretion, via the renin-angiotensin meChanism.There is also a decrease in plasma osmolality.# RBC & Haemoglobin: RBC volume is increased to the extent of 20-30%. Total increase in volume is about 350ml; the amount to be regulated by the increased demand of oxygen transport during pregnancy. Disproportionate increase in plasma and RBC volume produces a state of haemodilution during pregnancy. Thus, even though the total haemoglobin mass increases during pregnancy to the extent of 18-20 percent, there is apparent fall in haemoglobin concentration. At term the fall is about 2 gm5 from the non-pregnant value. There is simultaneous fall in number of red cells by 15-20% and the hematocrit level.# Blood changes in Pregnancy: Blood volume +30-40% Plasma volume + 40-50% RBC volume +20-30% Hb+18-20% Hematocrit Diminished. Changes in blood coagulation factors: Platelets Static or-15% Fibrinogen + 50% ESR 4 times increases