Recommended Care at 20 Weeks Gestation
At 20 weeks gestation, the woman should be advised to take iron supplementation to prevent anemia (Option B), as this is the standard of care recommended by the CDC and ACOG for all pregnant women starting from the first prenatal visit and continuing throughout pregnancy. 1, 2, 3
Iron Supplementation - The Priority Intervention
All pregnant women should receive 30 mg of elemental iron daily starting from the first prenatal visit, regardless of anemia status, to prevent iron deficiency anemia and optimize maternal-fetal outcomes 3
The prevalence of iron deficiency in pregnant women is approximately 18.6%, with 16.2% also having anemia, making this a critical preventive measure 1
Iron deficiency anemia when detected early in pregnancy is associated with a greater than 2-fold increase in the risk of preterm delivery 4
If anemia develops during pregnancy, the dose should be increased to 60-120 mg/day 1, 3
Low-dose iron supplementation (30 mg/day) improves birth weight even in non-anemic pregnant women and protects infants from iron-deficiency anemia 5
Why Not the Other Options at This Visit
Early Glucose Tolerance Testing (Option A)
Glucose screening is typically performed at 24-28 weeks gestation, not at 20 weeks 1
Early screening (before 20 weeks) is only indicated for women with specific risk factors such as pre-existing diabetes, obesity (BMI >30), or history of bariatric surgery 1
The standard approach uses either fasting glucose/OGTT at 24-28 weeks 1
24-Hour Urine Protein Test (Option C)
This test is not routinely performed at 20 weeks in uncomplicated pregnancies
It is indicated when there is clinical suspicion of preeclampsia or proteinuria, not as routine screening 1
While calcium supplementation (1.0-1.5 g daily) can reduce preeclampsia risk by approximately 50%, particularly in populations with low dietary calcium intake 1, 3, the 24-hour urine protein is not a screening tool at this gestational age
Additional Routine Care at 20 Weeks
Routine morphology ultrasound scan should be performed at 20-22 weeks gestation to assess fetal anatomy 1
Folic acid supplementation (0.4 mg daily for normal BMI, 4-5 mg for obesity or diabetes) should be continued through the first trimester and is typically discontinued by 20 weeks 1, 2
Vitamin D supplementation should be maintained to keep levels above 50 nmol/L 1, 2
Calcium supplementation of 1200-1500 mg daily in divided doses (including dietary intake) should be initiated, particularly in populations with low dietary calcium intake 1, 2
Common Pitfalls to Avoid
Do not delay iron supplementation - it should have been started at the first prenatal visit, but if not yet initiated, start immediately 3
Calcium and iron supplements should ideally be taken at different times (separated by at least 2 hours) as calcium can inhibit iron absorption 1, 2
Higher iron doses (>60 mg) are not recommended for prophylaxis due to potential negative effects on mineral absorption, oxidative pathways, and adverse gastrointestinal symptoms 5
Do not perform glucose screening at 20 weeks unless specific risk factors are present - wait until 24-28 weeks for routine screening 1