Iron Deficiency in Pregnancy Is Common, yet Many Aren't Being Screened for It

Jaleesa Baulkman

September 08, 2021

Many pregnant patients are not being screened for iron deficiency despite it being a common cause of anemia in pregnancy that could increase the risk of maternal and infant death.

Researchers analyzed data from 44,552 pregnant patients in Ontario, Canada, collected between 2013 and 2018 to determine the prevalence of ferritin testing, the standard test for iron deficiency, over the course of 5 years.

Their study, published in Blood Advances, revealed that only 59.4% of pregnant persons received a ferritin test, the standard test for iron deficiency. Of those pregnant persons, 25.2% were iron insufficient and 52.8% were iron deficient at least once during pregnancy.

They also found that 71% of these iron tests were ordered during the first trimester, when the risk of iron deficiency is lowest.

"We are not only missing a very large proportion of women who are iron deficient going into pregnancy, but we're missing those that become iron deficient later on in their pregnancies," study author Jennifer Teichman, MD, hematology resident at the University of Toronto, said in an interview. Researchers said iron deficiency during pregnancy is associated with maternal fatigue, cognitive dysfunction, depression, low birth weight, and poor brain development of the child.

Teichman explained that if iron deficiency during pregnancy is identified early enough, doctors would have enough time to treat the condition with iron supplements before the patient goes into delivery. She also explained prenatal vitamins, which contain some iron, do not contain enough of the mineral to fix iron deficiency.

"One really important point is that the amount of iron contained in a prenatal vitamin is really low," Teichman explained. "It's enough to make up the difference of the additional iron that she needs to sustain her pregnancy, but it's not enough to treat a woman who's already got low iron going into pregnancy. So there's a difference between a prenatal vitamin and true iron supplementation."

Researchers also found that those who came from a household with a low annual income were even less likely to receive a ferritin test, which was a troubling finding since women of lower socioeconomic status are more likely to be iron deficient in pregnancy.

"[This] says something about how we as health care providers are contributing to this gap in care," Teichman said. "Women of lower socioeconomic status sort of have a triple whammy: They're more likely to be iron deficient, they're less likely to have it diagnosed, and they're less likely to have it corrected."

Teichman and her colleagues took a unique approach by looking at isolated ferritin levels as opposed to complete blood counts, which is the typical screening for anemia in pregnancy, said Lissette Tanner, MD, MPH, FACOG, who was not involved with the study.

"Those who meet the criteria for anemia should be evaluated for the cause with initial suspicion for iron deficiency anemia, as that is the most common etiology," said Tanner, assistant professor of gynecology and obstetrics at Emory University, Atlanta.

The Centers for Disease Control and Prevention recommends screening for iron deficiency anemia in pregnant persons, in addition to universal iron supplementation to meet the iron requirements of pregnancy.

Additionally, the American College of Obstetricians and Gynecologists recommends that all pregnant persons be screened for anemia with a complete blood count in the first trimester and again between 24 and 28 weeks of pregnancy.

However, iron deficiency is completely missed by ACOG's recommendations, said Michael Auerbach, MD, of the department of medicine, Georgetown University, Washington.

"They recommend a [complete blood count] on all presenting pregnant women, but they do not recommend iron parameters, including a ferritin test, unless the mother is anemic," said Auerbach, who was not involved in the study. "I think those guidelines are in need of revision."

Teichman hopes her team's findings will motivate change in obstetric and hematologic guidelines that recommend routine prenatal testing.

"I think ferritin should be a part of routine prenatal testing," Teichman said. "And I also think that patients need to be empowered to ask what their iron levels are in pregnancy and providers need to know what a normal iron level is."

None of the experts interviewed for this story had financial conflicts of interest.

This article originally appeared on, part of the Medscape Professional Network.


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