USPSTF: Evidence Lacking to Screen for Iron Deficiency Anemia in Pregnancy

Second Draft Rec Finds Evidence Insufficient to Screen Young Children for Same Condition

April 06, 2015 02:30 pm Chris Crawford

Few data are available to show how widespread iron deficiency anemia is in pregnant women in the United States. Older data assessed by the U.S. Preventive Services Task Force (USPSTF) in making its 2006 recommendations related to this topic suggested the prevalence of iron deficiency in pregnant women to be almost 19 percent; of those, an estimated 16 percent had anemia. Rates tended to be higher in low-income and minority populations.

[Little girl with nose pressed against mom's pregnant belly]

The USPSTF recently revisited the topic, re-evaluating these earlier data, as well as research conducted since 2006, and subsequently posted a draft recommendation statement( reversing its previous recommendation to screen pregnant women for iron deficiency anemia.

In its 2006 recommendation,( the task force said that although no studies specifically addressed the accuracy and benefit of screening asymptomatic pregnant women for iron deficiency, fair evidence showed that treating those with iron deficiency anemia resulted in moderate benefits in health outcomes. Based on these findings, USPSTF members concluded that the potential benefits of routine screening for iron deficiency anemia in asymptomatic pregnant women outweighed the potential harms.

However, the USPSTF's latest evidence review( "found no good- or fair-quality studies on the benefits or harms of screening that would be applicable to the current U.S. pregnant population."

Story highlights
  • The U.S. Preventive Services Task Force (USPSTF) recently posted a draft statement that cited insufficient evidence to recommend screening pregnant women for iron deficiency anemia.
  • Just as it did in 2006, the USPSTF found insufficient evidence to determine the benefits and harms of iron supplementation in pregnant women.
  • A second draft recommendation found insufficient evidence to assess the benefits and harms of screening children ages 6 to 24 months for iron deficiency anemia.

According to Jennifer Frost, M.D., medical director for the AAFP Health of the Public and Science Division, "The (previous) recommendation was based on studies that showed the benefit of iron supplementation in asymptomatic anemic pregnant women. The assumption was made that if supplementation was beneficial, early recognition through screening would improve outcomes.

"However, a re-evaluation of the evidence for benefits of iron supplementation showed inconclusive results, as well."

Screening for anemia is a routine part of prenatal care for all pregnant women, Frost said, as is supplementation with prenatal vitamins (which contain iron).

"I do not think that this change in stance by the USPSTF will affect that," she said. "As an 'I statement,'( they are not saying, 'Don't screen,' just that there isn't sufficient evidence to prove a benefit of screening. As there are no serious harms of iron supplementation, and a relatively high rate of iron deficiency anemia, screening and supplementation will likely continue."

In 2006, the AAFP agreed with the USPSTF, mirroring its recommendations on screening for iron deficiency anemia. Now, the Academy will re-evaluate the latest evidence presented to update its own recommendations.

Iron Supplementation for Pregnant Women

Both in 2006 and in this draft recommendation, the USPSTF found insufficient evidence to determine the benefits and harms of routine iron supplementation in pregnant women.

"There are studies that show a link between iron deficiency and poor pregnancy outcomes," Frost said. "However, these studies are of poor quality. Better-quality studies have shown inconsistent results. The evidence also does not show improvement in these outcomes with routine supplementation. Because these studies were of fair or poor quality, they could not conclusively state that there is no benefit, so they continued with an 'I statement.'

"Again, because the risks associated with taking iron are minimal, and there may be benefit (although not proven), most clinicians will likely continue their current practice of routine supplementation."

Frost added that one of the many challenges of providing maternity care is the limited amount of high-quality evidence available to inform decisions.

"We use the best evidence that is available as we strive to improve outcomes and to ensure that we do no harm," she said.

Updated Recommendation for Small Children

A second draft recommendation just released found insufficient evidence to assess the benefits and harms of screening children ages 6 to 24 months( for iron deficiency anemia, which also is an update from the USPSTF's 2006 recommendation( on this topic.

The 2006 recommendation included a statement on iron supplementation in infants at increased risk for iron deficiency anemia that the USPSTF removed in the current draft recommendation.

"This recommendation was based on fair evidence that routine supplementation with iron-fortified formula and cereals in high-risk populations provided some benefit," Frost said. "Because of the current widespread use of iron-fortified formula and cereal, this recommendation is no longer needed."

She added that iron deficiency anemia in children is uncommon in the United States and that there is no proven benefit of screening.

"However, screening is still a common practice, as the American Academy of Pediatrics recommends routine screening for anemia in all infants at 12 months of age," Frost said.