Over 50% of Pregnant Women Face Iron Deficiency Risk! Beyond Affecting Baby’s Sex, These Adverse Effects on Mothers and Babies Arise from Iron Deficiency During Pregnancy

During the journey of pregnancy, a mother’s health and nutritional status directly impact the baby’s development. Most expectant mothers focus on supplementing sufficient nutrients like folic acid, calcium, and protein during pregnancy, but iron—an often overlooked element—is actually crucial for the health of both mother and baby. A recent study published in the top international journal Nature showed that iron deficiency in pregnant mice leads to sex reversal of their fetal mice embryos from male to female, resulting in the feminization of male fetuses. No clinical cases regarding the impact of iron deficiency during pregnancy on fetal sex differentiation have been reported, but the effects of iron deficiency during pregnancy on pregnant women and fetuses are relatively clear. This article will reveal the hazards of iron deficiency during pregnancy, especially its long-term health impacts on mothers, babies, and offspring, combined with the latest research, while introducing treatment methods for iron deficiency during pregnancy.

Iron: An Indispensable Core Element During Pregnancy

Iron is an essential trace element for the human body. Its main function is to help hemoglobin transport oxygen, and it participates in cellular energy metabolism and immune responses. For pregnant women, the demand for iron is twice that of usual—they not only need to supply sufficient oxygen to their own bodies but also provide oxygen support for the baby’s development. Additionally, iron is one of the key elements for the development of the fetal nervous system and brain.

Incidence and Etiology of Iron Deficiency During Pregnancy

Iron Deficiency Anemia (IDA) occurs in approximately 30%-60% of pregnancies worldwide, and about 50% of pregnancies are affected by iron deficiency or IDA. By the third trimester, nearly 75% of pregnant women will experience iron deficiency or anemia. Iron deficiency during pregnancy is mainly due to the physiological increase in iron demand during fetal and placental development. During pregnancy, the expansion of blood volume and the proliferation of red blood cells further exacerbate this demand.

Common Manifestations of Iron Deficiency During Pregnancy and Its Impacts on Maternal and Child Health

Iron deficiency during pregnancy usually presents as anemia. Pregnant women may feel abnormally fatigued, weak, and even dizzy and short of breath. As pregnancy progresses, iron deficiency worsens, and may even affect the pregnant woman’s normal life and work. According to data from the World Health Organization (WHO), approximately one-third of pregnant women worldwide suffer from anemia, with iron deficiency anemia being the most common type.

01 Impacts of Iron Deficiency During Pregnancy on the Mother

Preterm birth: Iron deficiency and anemia significantly increase the risk of preterm birth and the probability of delivering a preterm infant.
Cesarean section: Pregnant women with iron deficiency or anemia have a higher risk of cesarean section.
Preeclampsia and eclampsia: Maternal iron deficiency increases the risk of developing preeclampsia and eclampsia. Severe preeclampsia raises the risk of placental abruption.
Postpartum hemorrhage: Iron deficiency leads to more severe postpartum hemorrhage, increases the need for postpartum blood transfusion, and may result in serious postpartum complications.
Postpartum depression: Iron deficiency is closely associated with the occurrence of postpartum depression. Iron supplementation helps alleviate postpartum emotional issues.
Increased hospitalization risk: Anemic pregnant women are more likely to experience serious complications after childbirth and require transfer to the intensive care unit (ICU).

02 Impacts of Iron Deficiency During Pregnancy on the Fetus and Newborn

Low birth weight and small for gestational age (SGA): Iron deficiency increases the risk of delivering infants with low birth weight (<2500g) and small for gestational age. These infants face higher health risks, such as underdeveloped lungs and weakened immune systems.
Fetal distress: Fetuses of iron-deficient pregnant women are more prone to fetal distress (e.g., hypoxic state), which affects the development of the fetal heart and brain.
Neonatal iron deficiency: Infants may be born in an iron-deficient state, especially if the mother did not receive adequate iron supplementation during pregnancy. Approximately 14% of full-term infants have a serum ferritin level below 30μg/L at birth, which increases the risk of iron deficiency after birth.

03 Long-Term Health Impacts of Prenatal Iron Deficiency on Offspring

Neurodevelopmental issues: Prenatal iron deficiency has been shown to affect brain development, increasing the risk of future autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and other intellectual disabilities. Long-term neurodevelopmental impacts include difficulties with memory, processing speed, and emotional connection, which may persist into adulthood.
Intellectual developmental delay: Studies have shown that prenatal iron deficiency leads to limited cognitive development in newborns, such as inattention and learning difficulties, and these issues may persist into childhood and even adulthood.
Cardiovascular problems: Prenatal iron deficiency may also affect the development of the cardiovascular system, increasing the risk of future hypertension, obesity, and abnormal lipid metabolism.

Management of Iron Deficiency During Pregnancy

The guidelines for the management of iron deficiency during pregnancy issued by the American College of Obstetricians and Gynecologists (ACOG) include the following key recommendations:

01 Anemia Screening and Treatment

ACOG recommends anemia screening for all pregnant women, especially in the first trimester.

Universal iron supplementation: ACOG advises that all pregnant women should take iron supplements to meet the iron needs during pregnancy, typically recommending 27mg of elemental iron per day.

02 Diagnosis of Iron Deficiency

When diagnosing iron deficiency, ACOG recommends using a serum ferritin level below 30μg/L as the diagnostic criterion. Although there is no unified standard, ACOG supports the use of this threshold.

03 Treatment Plans for Anemia

For pregnant women diagnosed with anemia, ACOG recommends iron supplementation and indicates that oral iron supplementation is the preferred treatment method. Side effects of oral iron are common, but ACOG advises pregnant women to persist with treatment patiently and assess the therapeutic effect during follow-up reviews.

Use of intravenous iron supplementation: ACOG recommends considering intravenous iron supplementation when oral iron treatment is ineffective, especially for pregnant women who cannot tolerate oral iron or do not respond effectively to it. However, intravenous iron is usually administered only in the second or third trimester, as its safety in the first trimester has not been fully confirmed.