Iron Deficiency in Pregnancy Is Ubiquitous

Background: Iron deficiency anemia (IDA) is highly prevalent in pregnancy. It has been associated with increased maternal morbidity, peripartum complications, and impaired cognitive development in the offspring. Yet little attention has been given to IDA's antecedent, iron deficiency (ID).

The American College of Obstetricians and Gynecologists (ACOG) recommends screening anemic pregnant patients for iron deficiency (ID) but recommends against screening for ID among non-anemic pregnant women. Nevertheless, symptoms such as fatigue that are typically attributed to pregnancy physiology may in fact be attributed to ID.

In this study, we sought to quantify the prevalence of ID and fatigue symptoms in pregnant women at 23-29 weeks’ gestation and to examine whether ID was associated with increased risk of fatigue symptoms compared to those without ID.

Methods: We conducted a cross-sectional study of low-risk pregnant women receiving care at two large community obstetric practices. 75% identified as Hispanic/Latino, and 6% identified as African-American. Pregnant women were approached at their laboratory appointment for gestational diabetes screening (23-29 weeks’ gestation). Consenting patients had complete blood count, ferritin, and iron saturation measured, and each completed the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale to evaluate for ID-related fatigue. IDA was defined as ferritin <30 ng/mL or iron saturation <20%, and hemoglobin <11 g/dL. Iron deficiency without anemia (IDWA) was defined as ferritin <30 ng/mL with hemoglobin >11 g/dL.

Results: Among 122 approached patients, 110 (90%) consented. Ferritin <30 ng/mL was found in 98/110 (89%) pregnant women and ferritin <15 ng/mL was found in 76/110 (69%) pregnant women. IDA and IDWA were present in 24/110 (22%) and 76/110 (69%). The rate of screening positive for fatigue on the FACIT-Fatigue scale was similarly high among patients with IDA (10/24; 42%) and IDWA (42/76; 55%), compared to 20% (2/10) in patients without iron deficiency. Only nine participants (8%) had neither anemia nor ID, and only one patient with anemia did not have ID.

Conclusion: In this cross-sectional study of low-risk pregnant women at 23-29 weeks' gestation receiving prenatal care from community-based obstetricians, we found that iron deficiency (ID) is ubiquitous in pregnancy, with nearly 90% of pregnant women exhibiting low ferritin levels. This would frequently be missed if anemia were prerequisite for iron testing, as recommended by ACOG guidelines. We also found that pregnancy-associated fatigue is common in women with ID, including many of those who have IDWA. These findings highlight the need for routine iron deficiency screening in pregnancy to ensure timely intervention and optimize maternal and fetal health outcomes.