Study shows most pregnant women at risk for iron deficiency
A new study is shedding light on iron deficiency in pregnancy, which can lead to serious complications for both mother and baby.
Research shows most pregnant women are at risk for iron deficiency, with 4 out of 5 becoming iron-deficient by their third trimester. The study, recently published in the American Journal of Clinical Nutrition, and conducted in Ireland found that more than 80% of pregnant women experience iron deficiency. Based on the new findings, researchers are urging changes in guidelines and routine iron deficiency testing for all pregnant women.
“Despite growing evidence from multiple observational studies showing a high incidence of iron deficiency during pregnancy and its adverse effects on maternal and fetal health, there is currently a lack of consensus regarding routine screening for iron deficiency in non-anemic women during pregnancy,” says Dr. Rama Bhagavatula of the Department of Hematology and Cellular Therapy, AHN Cancer Institute. “This study highlights the high prevalence of iron deficiency throughout pregnancy and emphasizes the need for early screening and correction of iron deficiency to prevent adverse maternal and fetal outcomes.”
The Irish study tracked blood levels of iron in 641 pregnant women who had a successful delivery for the first time. Blood tests at 15, 20 and 33 weeks of pregnancy show iron deficiencies often appear later in pregnancy. In the study, none of the participants were iron-deficient in the first trimester, yet 80% showed iron deficiency by the third trimester. Currently, International Federation of Gynecology and Obstetrics (FIGO) guidelines recommend screening all pregnant women for iron deficiency, regardless of the presence or absence of anemia. In contrast, the United States Preventive Services Task Force (USPSTF) guidelines state insufficient outcome data to support routine screening.
“This lack of support is, in part, due to the absence of prospective randomized controlled trials,” says Bhagavatula. “Nevertheless, multiple observational and prospective studies have reported high incidences of iron deficiency and its adverse effects during pregnancy. In recent years, due to increased awareness, health-care providers have begun screening pregnant women for iron deficiency. For example, at Allegheny Health Network, we have implemented a network-wide recall system over the past three years to screen all pregnant women for iron deficiency and treat it promptly.”
During pregnancy, iron is essential to support the increasing red blood cell mass in the mother, promote placental growth, and support fetal development. As pregnancy progresses, the increased iron demands can deplete maternal iron stores, leading to iron deficiency and anemia. “This study is particularly significant because it is one of the largest to show longitudinal changes in iron deficiency throughout pregnancy in a high-resource setting,” Bhagavatula says. “It underscores that iron deficiency is not exclusive to lower-income or less-developed nations but also affects pregnant women across all socioeconomic strata.”
For mothers, iron deficiency can lead to anemia, which can cause fatigue, shortness of breath, and reduced exercise tolerance. Iron deficiency increases the risk of preterm labor, preeclampsia, postpartum hemorrhage, and the need for blood transfusion. It also raises the risk of postpartum depression. For babies, iron deficiency increases the risk of low birth weight and small-for-gestational-age infants. Additionally, it can adversely affect fetal brain development, leading to potential neurodevelopmental issues.
Pregnant women require more iron than can typically be provided by diet alone, and both the World Health Organization and Centers for Disease Control recommend iron supplementation. “While commonly used oral iron supplements can cause side effects such as constipation, bloating, and nausea, making them difficult for many pregnant women to tolerate, we provide strategies to minimize these side effects and optimize iron absorption,” says Bhagavatula. “For women who cannot tolerate oral iron or do not respond adequately to oral supplements and in the third trimester of pregnancy, intravenous iron supplementation is recommended. IV iron is effective, safe, and works more rapidly and efficiently than oral iron.”
Expectant mothers can also increase their dietary intake of iron through foods like lean meats, fish (such as tuna), beans, nuts, whole grains, iron-fortified bread, green vegetables, Brussels sprouts, dried prunes, and raisins. Consuming iron-rich foods with vitamin C-rich foods, such as citrus fruits, dark leafy greens and bell peppers can also enhance iron absorption. It’s helpful to avoid coffee, black tea, and calcium-rich foods two hours before and three to four hours after a meal, as calcium can inhibit iron absorption.
Women with pre-existing iron deficiency due to heavy menstrual periods, bleeding disorders, surgeries (such as gastric bypass), or conditions like celiac disease have elevated risk as are women carrying multiples (twins or triplets), those with short intervals between pregnancies, or those with low dietary iron intake due to factors such as a vegan diet or socio-economic circumstances.
“Iron deficiency in pregnancy is now a well-recognized condition with serious maternal and fetal consequences,” Bhagavatula says. “It is common but manageable. The key is early recognition and intervention. Screening for and treating iron deficiency should be a routine part of prenatal care for all pregnant women.”