One of the Largest Studies of its Kind Finds Early Intervention with Iron Delivered Intravenously During Pregnancy is a Safe and Effective Treatment for Anemia 

Anemia during pregnancy is a common occurrence and often due to iron deficiency. It is a global public health problem, affecting an estimated 37 percent of pregnant individuals, according to the World Health Organization. Iron deficiency anemia is associated with increased rates of pregnancy-related problems, such as going into labor prematurely, hemorrhaging and, in some cases, even death. For the infant, maternal iron deficiency also can have long-term implications on their overall health and development.

Current obstetric guidelines recommend that pregnant people who suffer from iron deficiency anemia take daily oral iron supplements and, in cases of persistent iron deficiency anemia, they may be administered iron intravenously, commonly in the third trimester. Nonetheless, anemia during pregnancy remains a global health problem.

In a new study to be presented today at the Society for Maternal-Fetal Medicine’s (SMFM) annual meeting, The Pregnancy Meeting™, researchers will unveil findings from a clinical trial in India that suggest that a single dose of iron delivered intravenously early in the second trimester is a safe and effective intervention for anemia during pregnancy.

The study was conducted across multiple sites in India and involved a total of 4,368 participants, making it one of the largest studies to date employing IV iron in pregnancy. India was selected because of the prevalence of anemia in the country, according to the study’s lead author, Richard Derman, MD, MPH, vice provost of global affairs and professor of obstetrics and gynecology at Thomas Jefferson University in Philadelphia.

Participants identified to have moderate anemia and iron deficiency prior to 17 weeks’ gestation were randomized into three groups. The first cohort received the current standard of care — daily oral iron supplementation. The second and third groups received two commonly used IV iron formulations for single dose infusion, and the only ones approved for use in India, ferric carboxymaltose (FCM) and ferric derisomaltose (FDM). The two primary outcomes researchers looked at were differences in the IV iron groups compared to oral iron in: 1) rate of low birthweight infants and 2) rate of participants who reverted to a non-anemic state by delivery.

Results found that while all three groups had achieved similar rates of “non-anemic status” (normal blood counts) at the time of delivery, those who received IV iron had significantly lower rates of needing additional non-study IV iron or a blood transfusion prior to delivery. In the FCM IV iron cohort, results showed a reduced incidence of low birthweight infants compared to oral iron.

“What’s unique about this study is that we did the iron intervention early in the second trimester. Many other studies comparing IV iron to oral iron are initiated in the third trimester,” says study co-author Rupsa C. Boelig, MD, MS, a maternal-fetal medicine subspecialist and associate professor at Thomas Jefferson University’s Sidney Kimmel Medical College. Boelig also serves as director of the University’s Department of Obstetrics and Gynecology Research Unit and associate director for the Maternal Fetal Medicine Fellowship. “Iron requirements increase dramatically during pregnancy. An additional 1 gram of iron is required for the developing fetus, and for placental storage. Such requirements increased dramatically during the second and trimester, so it’s much more difficult to catch-up if you’re intervening in the third trimester,” notes Boelig. “Studies have shown that maternal iron deficiency anemia early in pregnancy is most strongly correlated with adverse outcomes, including short-term infant outcomes such as low birthweight and longer-term childhood outcomes, including autism and schizophrenia. So there is a need to intervene earlier and aggressively address anemia.

“From this trial it is evident that single dose IV iron preparations are safe and easy to administer under proper supervision and facilities in order to treat anemia in pregnancy,” says Mrutyunjaya B. Bellad, MD, professor in the Department of Obstetrics and Gynecology at the KLE Academy of Higher Education and Research, J.N. Medical College in Belagavi, India. “We are immensely thankful to the pregnant women who participated in this trial for the benefit of the global pregnant women. We hope this should end the menace of anemia related complications. We thank all those who have contributed to this successful trial.” Researchers believe that new clinical guidelines should address the potential benefit of single dose IV iron as a primary treatment for moderate anemia due to iron deficiency during pregnancy.

The abstract was published in the January 2025 issue of Pregnancy, a new open-access journal and the first official journal for the Society for Maternal-Fetal Medicine. The full article is scheduled to be published in the American Journal of Obstetrics and Gynecology.