What is the cause and recommended health promotion for an 11-week pregnant individual experiencing fatigue and lightheadedness with a haemoglobin (Hb) level of 11.5 g/dL?

Physiologic Anemia of Pregnancy: Plasma Volume Expansion

The correct answer is A: Plasma volume expanded; eat iron-rich food. At 11 weeks gestation with hemoglobin 11.5 g/dL and symptoms of fatigue and lightheadedness, this patient has borderline physiologic anemia from pregnancy-related hemodilution, and requires iron supplementation and dietary counseling 1.

Understanding the Underlying Physiology

Plasma volume expansion is the primary physiologic mechanism causing these symptoms:

• All pregnant women develop physiologic anemia due to blood volume expansion and hemodilution, with plasma volume increasing 40-50% while red cell mass increases only 20-30% 2
• At 11 weeks gestation, hemoglobin <11 g/dL is considered anemic (the normal cutoff is >11 g/dL in the first trimester) 1, 3
• This patient's hemoglobin of 11.5 g/dL is borderline, but her symptoms of fatigue and lightheadedness indicate she is symptomatic from relative anemia 1
• The normal physiologic range for hemoglobin during pregnancy is 11.5-13.0 g/dL, with values outside this range associated with pregnancy complications and fetal growth retardation 4

Why the Other Options Are Incorrect

Option B (increased metabolism/caloric intake) is not the primary issue:

• While pregnancy does increase metabolic demands, this does not explain the specific symptoms of fatigue and lightheadedness with borderline hemoglobin 2
• The patient's symptoms are directly attributable to reduced oxygen-carrying capacity, not caloric deficit 1

Option C (decreased vascular resistance/antihypertensive treatment) is contraindicated:

• Decreased vascular resistance is a normal physiologic adaptation in pregnancy 2
• There is no indication for antihypertensive treatment in this patient with no mention of hypertension 2
• Starting antihypertensive medication would be harmful and potentially dangerous 2

Recommended Treatment Protocol

Iron supplementation is the cornerstone of management:

• Prescribe 60-120 mg of elemental iron daily as first-line treatment for iron deficiency anemia in pregnancy 1, 3
• Continue treatment until hemoglobin normalizes for gestational age, then reduce to a maintenance dose of 30 mg/day 1
• New evidence suggests intermittent dosing is as effective as daily dosing with fewer side effects 3

Dietary counseling should emphasize:

• Iron-rich foods including red meat, poultry, fish, legumes, and fortified cereals 1
• Vitamin C-containing foods (citrus fruits, tomatoes, peppers) taken with iron supplements to enhance absorption 1

Monitoring and Follow-Up

Reassess response to treatment systematically:

• Recheck hemoglobin after 4 weeks of treatment, expecting at least a 1 g/dL increase in hemoglobin or 3% increase in hematocrit 1
• If no response after 4 weeks despite compliance and absence of acute illness, further evaluation with MCV, RDW, and serum ferritin is necessary 1
• Refer to a physician familiar with anemia in pregnancy if hemoglobin drops to <9.0 g/dL or hematocrit <27.0% 1

Activity Recommendations Despite Symptoms

Physical activity should be maintained with modifications:

• Women with hemoglobin levels >10 g/dL who are symptomatic should consider reducing the intensity of prenatal exercise but remain physically active 1
• Pregnant women should accumulate at least 150 minutes of moderate-intensity physical activity each week to achieve clinically meaningful reductions in pregnancy complications 2
• Pregnant women who experience lightheadedness, nausea, or feel unwell when exercising flat on their back should modify their exercise position to avoid the supine position 2

Critical Pitfalls to Avoid

Do not dismiss symptoms as "normal pregnancy":

• Fatigue and lightheadedness require evaluation and treatment, not reassurance alone 1
• Symptomatic anemia at 11 weeks warrants intervention even with borderline hemoglobin levels 1, 5

Do not delay iron supplementation:

• Start treatment based on clinical suspicion without waiting for ferritin results if iron deficiency is likely 1
• Mild anemia with hemoglobin of 10.0 g/dL or higher and mildly low or normal MCV is likely iron deficiency anemia, and a trial of oral iron can be both diagnostic and therapeutic 3

Do not restrict physical activity unnecessarily:

• Complete inactivity could result in increased risk of adverse pregnancy outcomes 1
• Encourage continued activity with intensity modifications as needed 2