Iron Supplementation to Prevent Anemia
For this healthy 20-week pregnant woman with no risk factors, advise iron supplements to prevent anemia (Option C). This is the only evidence-based intervention appropriate for her current clinical scenario.
Why Iron Supplementation is the Correct Answer
Iron supplementation during pregnancy consistently increases hemoglobin and serum ferritin levels while reducing the prevalence of iron deficiency anemia, which affects 20-40% of pregnant women and is associated with preterm delivery, low birth weight, and perinatal death. 1, 2, 3
Recommended Iron Dosing Strategy
Low-dose iron supplementation (30-40 mg elemental iron daily) is appropriate for routine prophylaxis in healthy pregnant women without documented iron deficiency. 1, 4
Iron requirements in the second half of pregnancy cannot be met through diet alone, even with adequate nutritional intake. 1
For women with documented iron deficiency (ferritin <30 μg/L), higher doses of 80-100 mg elemental iron daily are indicated. 1
Intermittent dosing (every other day) is as effective as daily dosing with fewer gastrointestinal side effects. 3
Timing and Administration
Iron supplements should be taken at bedtime or between meals to optimize absorption. 1
Screening for anemia should occur in the first trimester and again at 24-28 weeks gestation with a complete blood count. 3
Why the Other Options Are Incorrect
Early Glucose Tolerance Test (Option A) - Not Indicated
Early glucose screening is recommended only for women with risk factors for undiagnosed type 2 diabetes, including history of gestational diabetes, previous macrosomia, obesity (BMI >30), metabolic syndrome, age >35 years, vascular disease, or high-risk ethnicity. 5
This patient has none of these risk factors (BMI 25, age 20 weeks, no medical history), making early screening inappropriate. 5
24-Hour Urine Protein (Option B) - Not Indicated
Proteinuria screening is not indicated in normotensive pregnant women without hypertension. 5
This patient's blood pressure is 110/70 mmHg, which is completely normal. 5
Proteinuria assessment is only performed when evaluating for preeclampsia, which requires hypertension (≥140/90 mmHg) as a prerequisite. 6
Low-Dose Aspirin for Preeclampsia Prevention (Option D) - Not Indicated
Low-dose aspirin (75-162 mg daily) is recommended only for women at high risk or moderate risk for preeclampsia, starting before 16 weeks but definitely before 20 weeks gestation. 6
High-risk factors include: prior preeclampsia, chronic hypertension, chronic kidney disease, autoimmune disease, diabetes, or antiphospholipid syndrome. 6
Moderate-risk factors include: first pregnancy in women >40 years, pregnancy interval >10 years, BMI >35 kg/m², family history of preeclampsia, or multiple pregnancies. 6
This patient has none of these risk factors (BMI 25, normal BP, no medical history, no family history), making aspirin prophylaxis inappropriate. 6, 5
Clinical Pearls and Common Pitfalls
Do not prescribe iron doses exceeding 100 mg daily for routine prophylaxis, as higher doses increase oxidative stress, impair absorption of other divalent metals, and cause gastrointestinal side effects without additional benefit. 1, 4
Iron deficiency anemia is associated with adverse fetal neurodevelopmental outcomes, including effects on intelligence and behavioral development. 1
Even in non-anemic pregnant women, low-dose iron supplementation may improve birth weight. 4
The physiologic iron requirements during pregnancy total approximately 1000 mg (300 mg for fetus/placenta, 500 mg for maternal red cell mass expansion, 200 mg for normal losses), which requires body iron reserves of ≥500 mg at conception to maintain adequate balance. 1