Suboptimal iron deficiency screening in pregnancy and the impact of socioeconomic status in a high-resource setting

Abstract

Iron deficiency anemia (IDA) in pregnancy is associated with poor maternal and childhood outcomes, yet ferritin testing, the standard test for iron deficiency (ID), is not considered part of routine prenatal bloodwork in Canada. We conducted a retrospective cohort study of 44,552 pregnant patients with prenatal testing at community laboratories in Ontario, Canada to determine the prevalence of ferritin testing over five years. Secondary objectives were to determine the prevalence and severity of ID, and to identify clinical and demographic variables that influence the likelihood of ID screening. 59.4% of patients had a ferritin checked during pregnancy; 71.4% were ordered in the first trimester, when the risk of ID is lowest. Excluding patients with abnormally elevated ferritins, 25.2% were iron insufficient (30-44 µg/L) and 52.8% were iron deficient (≤29 µg/L) at least once in pregnancy. 8.3% were anemic (hemoglobin <105 g/L). The proportion of anemic patients with a subsequent ferritin test in pregnancy ranged from 22% to 67% in the lowest and highest anemia severity categories, respectively. Lower annual household income was negatively associated with the odds of a ferritin test; compared to those in the fifth (i.e. highest) income quintile, the odds of ferritin testing for patients in the first, second, and fourth quintiles were 0.83 (95%CI 0.74-0.91), 0.82 (95%CI 0.74-0.91), and 0.86 (95%CI 0.77-0.97), respectively. These data highlight gaps in prenatal care and issues of health equity that warrant harmonization of obstetrical guidelines to recommend routine ferritin testing in pregnancy.

Evaluating test utilization for anemia during pregnancy

“…A Canadian study performed in a high-resource setting found that screening for iron deficiency was missed in 40% of pregnancies. 18 Our study found similar trends in lack of screening through laboratory tests.…”

“…As such, appropriate screening to identify iron deficiency is imperative for early prevention. A Canadian study performed in a high‐resource setting found that screening for iron deficiency was missed in 40% of pregnancies 18 …”

Associations of Food and Nutrient Intake with Serum Hepcidin and the Risk of Gestational Iron-Deficiency Anemia among Pregnant Women: A Population-Based Study

“…This corresponds to a progressive rise in gestational IDA in the first, second, and third trimesters: 2.7%, 2.2%, and 10.8%, respectively [ 3 ]. However, a recent survey showed an increasing trend of gestational ID (23.8%) in the first trimester in 2021 [ 4 ]. Gestational IDA is associated with the risk of maternal mortality and both cognitive and behavioral abnormalities of neonates [ 5 , 6 ].…”

Screening, Treatment, and Monitoring of Iron Deficiency Anemia in Pregnancy and Postpartum

“…In addition to dietary access, Teichman et al identified that ferritin screening was significantly lower between high‐ and low‐income households (odds ratio [OR], 0.83; 95% CI, 0.7‐0.9). These data suggest that individuals with low income are less likely to be screened for ferritin deficiency in pregnancy, which delays the diagnosis and treatment of iron deficiency and developing anemia 35 …”

“…These data suggest that individuals with low income are less likely to be screened for ferritin deficiency in pregnancy, which delays the diagnosis and treatment of iron deficiency and developing anemia. 35 Additional clinical considerations include chronic inflammation and infection during pregnancy, as these may falsely elevate ferritin levels used to screen for iron deficiency anemia. In these situations, TSAT is a more accurate measure of iron storage 22,36 because TSAT levels are less influenced by chronic infections or inflammation.…”