Pregnancy : Blood Changes During Pregnancy

During pregnancy, the female body undergoes numerous physiological changes to support fetal growth and development. These changes affect nearly every organ system, including the hematologic system. The levels of estrogens (estradiol) and progesterone increase progressively, influencing hepatic metabolic, synthesis, and excretory functions. The phenomenon of hemodilution, secondary to the increase in plasma volume, leads to decreased serum protein concentrations and altered liver function test values.

In a normal pregnancy, the maternal blood volume increases by about 30% above baseline due to elevated levels of estrogen and aldosterone, which cause the kidneys to retain more fluid. This increased fluid volume is accompanied by a higher number of erythrocytes, resulting in up to 1 to 2 liters of excess blood in the maternal circulatory system at delivery.

Key hematologic changes during pregnancy include physiologic anemia, expanded plasma volume, mild thrombocytopenia, a mild prothrombotic state, and mild neutrophilia in some individuals. These adaptations are essential for meeting the metabolic demands of pregnancy and preparing for the hemostatic challenges of childbirth.

Understanding these changes is crucial for healthcare providers to interpret laboratory results accurately and manage pregnancy-related conditions effectively. The following table summarizes the key changes in the blood profile during pregnancy, highlighting the...