IV iron therapy safe and effective for pregnant patients

IV iron therapy safe and effective for pregnant patients | Image Credit: © Rob Byron - © Rob Byron - stock.adobe.com.

Intravenous (IV) iron therapy can be safely administered without significant maternal or fetal safety concerns in obstetrical clinics, according to a recent study published in Pregnancy.

Over 1 in 3 pregnant patients worldwide experience iron deficiency anemia (IDA), leading to over half of antepartum anemia cases and severe adverse maternal and neonatal outcomes. Antenatal oral iron supplementation is often used to reduce the risk of IDA. However, while oral administration is cost-effective, it is often limited by poor absorption.

“Despite… advantages, IV iron administration is often limited due to outdated beliefs regarding potential side effects, such as anaphylaxis,” wrote investigators. “This practice necessitates the use of specialized infusion centers or hospital settings, primarily due to elevated costs and the requirement for resource utilization.”

IV iron regimens and monitoring

The retrospective chart review study was conducted to assess maternal and fetal outcomes following IV iron therapy administration in an outpatient obstetric clinic. Data was obtained from electronic medical records between January 2017 and June 2024.

Participants included pregnant patients receiving antenatal IV iron infusions at the antenatal testing center. This regimen was given to patients with poor response to oral iron, hemoglobin (Hgb) under 10 g/dL at 34 weeks’ gestation or later, or anticipated delivery before adequate oral iron repletion.

Iron sucrose and ferric carboxymaltose regimens were available, with the former including 2 doses of 300 mg IV 1 week apart or 3 doses of 200 mg IV 1 week apart. The latter regimen included 2 doses of 750 mg IV 1 week apart. Investigators collected patient vital signs at arrival, halfway through infusion, and at completion.

Data collection and study outcomes

Infusion cessation for at least 15 minutes was employed to manage mild adverse reactions, while moderate reactions were managed through IV saline bolus and possible corticosteroids to infusion cessation and monitoring. These methods were also used to manage severe reactions, alongside transfer to the hospital if needed.

RedCap software was used to collect and abstract data, including demographic and medical history characteristics. The safety and feasibility of IV iron infusion in an obstetric clinic setting were reported as the primary outcome. Change in Hgb levels, timing of last IV iron infusion before delivery, maternal outcomes, and neonatal outcomes were also reported.

There were 417 participants included in the final analysis, 29.5% of whom were White, 14.9% Black, 10.5% Asian, 39.2% other race or ethnicity, and 5.1% not reported. Private insurance was reported in 53.4%, Medicaid in 43.5%, and being uninsured in 3.1%. Iron sucrose was provided to 87.3% and ferric carboxymaltose to 12.7%.

Hemoglobin outcomes

Participants had a mean gestational age of 31.7 ± 4.6 weeks at the first infusion, 32.3 ± 4.4 weeks at the second, and 33.0 ± 4.7 weeks at the third. At baseline, the study population had a mean ferritin of 13.9 ± 26.4 ng/mL.

Hgb significantly increased between diagnosis and delivery, from 9.7 g/dL to 11.2 g/dL. In patients receiving 2 or fewer IV iron infusions, the mean Hgb rose from 10.1 g/dL to 11.5 g/dL. In those with 3 or more doses, the mean Hgb rose from 9.3 to 10.9. These changes were 1.4 and 1.6 g/dL, respectively, indicating similar improvements from 3 vs 2 doses.

However, a significantly greater improvement was observed from doses of 600 mg or more vs those under 600 mg, with increases in mean Hgb of 1.50 and 0.94 g/dL, respectively. Side effects were reported in 11.5% of patients, though only 0.5% of cases were terminated early because of adverse events.

Implications

The increase in mean Hgb was greater in patients receiving IV iron infusions more than 10 days before delivery, at 1.5 g/dL vs 1.1 g/dL in those receiving infusions less than 10 days before delivery. Overall, safety, feasibility, and efficacy were observed for IV iron infusion in pregnancy without fetal monitoring or hospital-based infusion.

“Our results provide practical guidance for the broader implementation of outpatient IV iron protocols, which have the potential to improve access to care and reduce healthcare resource utilization,” wrote investigators.

References

1. Murrin EM, LeBeau OS, Singer L. Effectiveness and safety of intravenous iron therapy in outpatient obstetrical clinic for treatment of iron-deficiency anemia during pregnancy. Pregnancy. 2025. doi:10.1002/pmf2.70067
2. Abu-Ouf NM, Jan MM. The impact of maternal iron deficiency and iron deficiency anemia on child's health. Saudi Med J. 2015;36(2):146-9. doi:10.15537/smj.2015.2.10289