(117) Early Pregnancy Serum Ferritin in the Non-Anemic Patient as a Predictor of Anemia at Delivery

We performed a prospective observational pilot study of non-anemic, singleton pregnancies. Women with multifetal gestation, iron supplementation, vaginal bleeding, chronic illness, hemoglobinopathies, or prior bariatric surgery were excluded. Iron studies (ferritin, transferrin, iron, total iron binding capacity) were collected before 23 weeks of gestation and blinded to their obstetric providers. Primary outcome: maternal anemia (hemoglobin < 11 grams/dL) at admission for delivery. Statistical analysis included Chi square and student t-tests (p < 0.05).

Results: One hundred and five women were enrolled and 98 delivered at our institution with 22 (22%) developing anemia at admission for delivery. An ROC curve identified an early ferritin value <26.4 micrograms/L in prediction of anemia (AUC=0.74; p< 0.001). Patients were divided into low ferritin (n=37) and normal ferritin (n=68) groups within the identified cutoff. Groups were similar in age, race, parity, obesity, and 1^st trimester hemoglobin. Median gestational age at enrollment was 15 weeks with mean ferritin values of 17±4.9 and 70.52±8.4 micrograms/L, for low and normal ferritin, respectively (p < 0.001). The low ferritin group had lower mean hemoglobin values in the third trimester (10.9±1.1 vs 11.6±0.9 g/dL, p=0.01) and at admission (11.5±1.1 vs 12.1±1.1 g/dL, p=0.007) with a higher rate of anemia in the 3rd trimester (62% vs 19%, p=0.002) and at admission for delivery (43% vs 11%, p=0.0004). With multivariate logistic regression, only ferritin < 26.4 micrograms/L was an independent predictor of anemia at admission (OR 5.12, 95% CI 1.71-15.35; p=0.003).

Conclusion: A low ferritin level <26.4 micrograms/L in non-anemic women in early pregnancy is predictive of anemia at delivery. Ferritin may be a potential screening tool to identify women at risk of developing anemia in pregnancy to allow for early intervention.