ABSTRACT
The study was conducted to investigate changes occurring in the blood during the three trimesters of pregnancy [three months trimester], the study covered a total number 1015 pregnant women [18-35 years old], all were healthy and living under good nutritional standard. Results showed a none significant change in: total erythrocytes count, and blood glucose concentration packed cell volume [PCV], hemoglobin concentration [Hb] increased significantly during the first trimester, total white blood cell [WBCs] and percentage of neutrophils decreased significantly during this trimester, while total cholesterol concentration and total biliruhin both direct and indirect and bilirubin decreased during the first and second trimester of pregnancy. During these trimesters, serum protein [total] and albumin rose significantly during the first trimester while concentration of and globulins decreased significantly during these periods, the results of this investigation, indicate presence of various changes in the blood both physical and biochemical during different trimesrers of pregnancy which may reflect various metabolic and honuonal changes occurring in pregnancy