Physiological anaemia during pregnancy is a result of?

IGNOU Post B. SC. Nursing entrance-2019

Obstetrics and Midwifery Nursing

Easy

Appeared in: IGNOU Post B. SC. Nursing entrance-2019

Explanation

Physiological anemia of pregnancy is caused by a disproportionate increase in plasma volume compared to the red blood cell (RBC) mass.
Plasma volume expands by approximately 40-50%, while the RBC mass only increases by about 20-30%.
This phenomenon, known as hemodilution, leads to a decrease in the concentration of hemoglobin and hematocrit, even though the total number of red blood cells is elevated.
It is a normal adaptation to meet the metabolic demands of the fetus and protect the mother from blood loss during delivery.

Option B: Decreased dietary intake leads to pathological anemias, such as iron-deficiency anemia, which is a disease state, not the normal physiological anemia of pregnancy.
Option C: Pregnancy stimulates erythropoiesis (RBC production) due to hormonal changes and increased erythropoietin levels; it does not decrease it.
Option D: The liver's detoxification role, while important, is not directly related to the concentration of red blood cells or the mechanism of physiological anemia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiological Anemia in Pregnancy as background academic context rather than a clinical decision trigger.
Nurses must differentiate between physiological anemia and pathological anemia. While a slight drop in hemoglobin is normal (nadir around 32-34 weeks), values below 11 g/dL in the first trimester or 10.5 g/dL in the second/third should be investigated for underlying pathology.
Patient education is crucial. Nurses should explain that this is a normal change but emphasize the importance of iron and folic acid supplementation to support the increased RBC production and prevent a true deficiency.
Monitoring for symptoms of severe anemia, such as excessive fatigue, pallor, shortness of breath, and tachycardia, is a key nursing responsibility throughout pregnancy.

How to Approach the Question

Identify the core concept: The question asks for the cause of 'physiological' anemia in pregnancy. The keyword 'physiological' implies a normal, adaptive process, not a disease state.
Analyze the options in the context of normal pregnancy changes. Consider what happens to blood components during gestation.
Evaluate Option A (Increased blood volume): Recall that plasma volume increases significantly during pregnancy. This is a major physiological change. Consider how this would affect the concentration of red blood cells.
Evaluate the other options: 'Decreased intake' and 'decreased production' (erythropoiesis) suggest a deficiency or pathology, which contradicts the term 'physiological'. 'Liver detoxification' is a different body system and not directly linked to red cell concentration.
Synthesize the information: The massive increase in plasma volume dilutes the red blood cells, which is the definition of hemodilution or physiological anemia. Therefore, increased blood volume is the direct cause.

Concept Tested & Keywords

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