What is the cause and recommended health promotion for an 11-week pregnant individual with fatigue, lightheadedness, and a hemoglobin (Hb) level of 11.5?

Plasma Volume Expansion is the Cause; Iron-Rich Foods are the Health Promotion

The correct answer is A: Plasma volume expanded; eat iron-rich food. This patient's symptoms result from physiologic hemodilution of pregnancy, and while her hemoglobin of 11.5 g/dL is technically at the borderline of normal for first trimester, her symptomatic presentation warrants iron supplementation and dietary counseling 1, 2.

Understanding the Underlying Physiology

• All pregnant women develop physiologic anemia due to plasma volume expanding 40-50% while red cell mass increases only 20-30%, creating a relative hemodilution 1.
• At 11 weeks gestation, hemoglobin <11 g/dL is considered anemic, making this patient's value of 11.5 g/dL borderline but her symptoms of fatigue and lightheadedness indicate she is symptomatic from relative anemia 2.
• The normal physiologic range for hemoglobin during pregnancy is 11.5-13.0 g/dL, and values outside this range are associated with pregnancy complications 3.

Why the Other Options Are Incorrect

• Option B (increased metabolism/caloric intake): While metabolism does increase during pregnancy, this does not explain the specific symptoms of fatigue and lightheadedness in the context of borderline hemoglobin 1.
• Option C (decreased vascular resistance/antihypertensive treatment): Vascular resistance does decrease in pregnancy, but this patient has no indication of hypertension requiring treatment. Antihypertensive treatment is only indicated for SBP ≥140 mmHg or DBP ≥90 mmHg 4.
• Option D (increased fetal oxygen demand/oxygen supplement): Oxygen supplementation has no role in managing physiologic anemia of pregnancy and is not indicated for this clinical scenario 1, 2.

Recommended Treatment Protocol

Iron supplementation should be initiated immediately:

• Prescribe 60-120 mg of elemental iron daily as first-line treatment 1, 2.
• Continue treatment until hemoglobin normalizes for gestational age, then reduce to maintenance dose of 30 mg/day 2.
• Recheck hemoglobin after 4 weeks, expecting at least a 1 g/dL increase 1, 2.

Dietary counseling is essential:

• Emphasize iron-rich foods including red meat, poultry, fish, legumes, and fortified cereals 1, 2.
• Recommend vitamin C-containing foods (citrus fruits, tomatoes, peppers) taken with iron supplements to enhance absorption 1, 2.

Physical Activity Recommendations Despite Symptoms

Do not restrict physical activity unnecessarily:

• Pregnant women should accumulate at least 150 minutes of moderate-intensity physical activity each week to achieve clinically meaningful reductions in pregnancy complications 4, 1.
• Women with hemoglobin >10 g/dL who are symptomatic should consider reducing the intensity of prenatal exercise but remain physically active 1, 2.
• Complete inactivity could result in increased risk of adverse pregnancy outcomes including gestational diabetes, pre-eclampsia, and gestational hypertension 4, 1.

Critical Pitfalls to Avoid

• Never dismiss fatigue and lightheadedness as "normal pregnancy symptoms" without addressing the anemia - these symptoms require evaluation and treatment, not reassurance alone 1, 2.
• Do not delay iron supplementation while waiting for ferritin results if clinical suspicion for iron deficiency is high 2.
• Do not advise complete bed rest or activity restriction - this increases risk of pregnancy complications 4, 1.