Postpartum IV iron is associated with sustained hemoglobin improvement at 6 months

A single infusion of intravenous ferric carboxymaltose (IV FCM) administered in the immediate postpartum period was superior to twice-daily oral iron in achieving a non-anemic hemoglobin level at 6 weeks, with benefits persisting through 6 months postpartum, according to results from a large international randomized controlled trial conducted across the NICHD Global Health Network.

The trial enrolled 4857 postpartum mothers across 8 international sites, screening participants between 6 and 48 hours after delivery. Women with moderate anemia—defined as hemoglobin between 7.0 and 9.9 g/dL—were randomly assigned to either a single intravenous infusion of IV FCM of up to 1 g or oral iron 60 mg twice daily continued through 6 months.

"What we found was that a single dose intravenous iron infusion in that immediate postpartum period was better than oral iron in achieving a non-anemic state, or a hemoglobin of at least 11 at 6 weeks postpartum," said Rupsa Boelig, MD, MS, an associate professor at Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, Pennsylvania.

Those randomly assigned to IV FCM were significantly more likely to achieve a hemoglobin of at least 11.0 g/dL at 6 weeks (RR 1.25; 95% CI, 1.20–1.29). The benefit was consistent across regions, including South Asia (RR 1.20; 95% CI, 1.14–1.25) and sub-Saharan Africa (RR 1.37; 95% CI, 1.29–1.46), and was observed across baseline hemoglobin levels, with greater benefit seen at lower starting values. IV FCM also produced significantly greater hemoglobin improvement at 6 weeks (MD 0.69 g/dL; 95% CI, 0.60–0.77), with the effect persisting at 6 months (MD 0.45 g/dL; 95% CI, 0.36–0.54), although statistical significance at 6 months could not be formally concluded due to hierarchical testing.

No difference in rates of postpartum depression was observed at 6 weeks (RR 0.87; 95% CI, 0.64–1.19) or 6 months (RR 1.06; 95% CI, 0.73–1.54), although Boelig noted that overall rates of postpartum depression were lower than anticipated.

Boelig emphasized the longer-term implications of the findings.

"Immediate postpartum anemia can and does persist for months, especially if not managed," she said. "So you can take these findings and think about what is the best way to manage postpartum anemia and really set our patients up for success, both in future life as well as future reproductive and pregnancy health." She noted that multiparity is among the strongest risk factors for anemia in subsequent pregnancies, making postpartum iron repletion a potentially important point of intervention.

On safety, serious adverse events related to the IV FCM infusion occurred in fewer than 1% of participants. Boelig flagged a known low rate of hypophosphatemia associated specifically with IV FCM, noting that although it is rarely clinically significant, it warrants consideration in individual patients. She also stressed that infusions should be administered by trained staff in settings equipped to recognize and manage potential infusion reactions.

Regarding implementation, Boelig identified the delivery hospitalization as a particularly practical window for administration.

"The immediate postpartum hospitalization really provides a convenient point of intervention," she said, while noting that IV FCM can also be administered in outpatient settings.

"Postpartum follow up is not always great—we know moms are busy taking care of their children and not necessarily taking care of themselves."

This trial was funded by the Gates Foundation through the Foundation for the Foundation for the National Institutes of Health with additional support provided by the Eunice Kennedy Shriver National Institute of Child Health and Human Development through grants to the Global Network for Women’s and Children’s Health Research.

Reference:

1. Single-dose intravenous iron vs oral iron for postpartum anemia: a multi-center randomized controlled trial (PRIORITY). Presented at: Society for Maternal-Fetal Medicine 2026 Pregnancy Meeting. February 8-13, 2026. Las Vegas, Nevada. Abstract LBA01