Associations of the pre-pregnancy weight status with anaemia and the erythropoiesis-related micronutrient status

Pathophysiology and management of iron deficiency anaemia in pregnancy: a review

According to World Health Organization (WHO), iron deficiency anaemia (IDA) is considered the most prevalent nutritional deficiency worldwide, affecting approximately 30% of the global population. While gastrointestinal bleeding and menstruation in women are the primary causes of IDA, insufficient dietary iron intake and reduced iron absorption contribute to the condition. The aim of IDA treatment is to restore iron stores and normalise haemoglobin levels in affected patients. Iron plays a critical role in various cellular mechanisms, including oxygen delivery, electron transport, and enzymatic activity. During pregnancy, the mother's blood volume increases, and the growing foetus requires a significant increase in iron. Iron deficiency during pregnancy is associated with adverse outcomes such as maternal illness, low birth weight, preterm birth, and intrauterine growth restriction. Iron supplementation is commonly used to treat IDA; however, not all patients benefit from this therapy due to factors such as low compliance and ineffectiveness. In the past, IV iron therapy was underutilised due to its unfavourable and occasionally unsafe side effects. Nevertheless, the development of new type II and III iron complexes has improved compliance, tolerability, efficacy, and safety profiles. This article aims to provide an updated overview of the diagnosis and management of IDA during pregnancy. It will discuss the advantages and limitations of oral versus intravenous iron and the pathophysiology, diagnosis, treatment, and overall management of IDA in pregnancy.

Relationships between Dietary Patterns and Erythropoiesis-Associated Micronutrient Deficiencies (Iron, Folate, and Vitamin B12) among Pregnant Women in Taiwan

Globally, anemia affects 56 million pregnant women, especially women with a low household income. Functional erythropoiesis requires a constant supply of micronutrients, and the demands significantly increase during fetal development. This study aims to identify dietary patterns for preventing gestational erythropoiesis-associated micronutrient deficiencies (e.g., iron, folic acid, and vitamin B₁₂). A Nationwide Nutrition and Health Survey in Pregnant Women, Taiwan (NAHSIT-PW), was conducted between 2017 and 2019. Data on baseline information, diet, anthropometrics, and blood biochemistry were collected during a prenatal visit. Dietary patterns were identified using a reduced rank regression (RRR). Erythropoiesis-related micronutrient deficiencies were defined as single, double, and triple micronutrient deficiencies of an iron deficiency, folate depletion, and a vitamin B₁₂ deficiency. In total, 1437 singleton pregnancies aged ≥20-48 years were included in the analysis. Prevalences of normal nutrition, and single, double, and triple erythropoiesis-related micronutrient deficiencies were 35.7%, 38.2%, 18.6%, and 7.5%, respectively. Anemic pregnant women with a low household income had the highest prevalence rates of double (32.5%) and triple (15.8%) erythropoiesis-related micronutrient deficiencies. Dietary pattern scores were positively correlated with nuts and seeds, fresh fruits, total vegetables, breakfast cereals/oats and related products, soybean products, and dairy products but negatively correlated with processed meat products and liver, organs, and blood products. After adjusting for covariates, the dietary pattern had 29% (odds ratio (OR): 0.71; 95% confidence interval (CI): 0.055-0.091, p = 0.006)) and 43% (OR: 0.57; 95% CI: 0.41-0.80, p = 0.001)) reduced odds of having double and triple erythropoiesis-related micronutrient deficiencies for those pregnant women with a low household income. For those women with anemia, dietary patterns had 54% (OR: 046, 95% CI: 0.27-0.78) and 67% (OR: 0.33; 95% CI: 0.170.64) reduced odds of double and triple erythropoiesis-related micronutrient deficiencies. In conclusion, increased consumption of breakfast cereals and oats, nuts, and seeds, fresh fruits and vegetables, soybean products, and dairy products may protect women against erythropoiesis-related micronutrient deficiencies during pregnancy.

Polymorphisms of haptoglobin modify the relationship between dietary iron and the risk of gestational iron-deficiency anemia

PURPOSE

To assess whether polymorphisms of haptoglobin (Hp) modify the relationship between dietary iron and the risk of gestational iron-deficiency anemia (IDA).

METHODS

This study analyzed 1430 singleton pregnant women aged 20 ~ ≤ 48 years from the 2017-2019 National Nutrition and Health Survey of Pregnant Women in Taiwan. Sociodemographic, blood biochemical, Hp phenotype, and 24-h dietary recall data were collected. Erythropoiesis-related total prenatal supplementation was defined as the reported use of multivitamins and minerals, vitamin B complex, folate, and iron.

RESULTS

Distributions of the Hp 1-1, Hp 2-1, and Hp 2-2 phenotypes were 13.6, 39.8, and 46.5%, respectively. Women with the Hp 1-1 phenotype had the lowest mean levels of serum ferritin (p-trend = 0.017), the highest prevalence of gestational ID (p-trend = 0.033) as well as the highest prevalence of gestational IDA (did not reach statistical differences, p-trend = 0.086). A gene-diet interaction on serum ferritin was observed between the Hp 1 and Hp 2 (2-1/2-2) alleles (p < 0.001). An adjusted multivariate logistic regression showed that compared to those with a normal blood iron status and who reported using erythropoiesis-related total prenatal supplements, those who did not had a 4.05-fold [odds ratio (OR) = 4.05 (95% confidence interval (CI) 2.63-6.24), p < 0.001] increased risk of gestational IDA. The corresponding ORs for carriers of the Hp 1 and Hp 2 alleles were 4.78 (95% CI 1.43-15.99) and 3.79 (95% CI 2.37-6.06), respectively.

CONCLUSION

Pregnant women who are Hp 1 carriers are at increased risk for developing IDA if they do not meet the recommended dietary allowance for iron or use erythropoiesis-related prenatal supplements.

Iron Deficiency Anemia in Pregnancy

Through its functions in oxygen delivery, electron transport, and enzymatic activity, iron is crucial for the operation of all cells. High metabolic rate cells need more iron and are more likely to malfunction when there is an iron deficit. Since the mother's blood volume expands during pregnancy, and the fetus grows and develops, there is a sharp increase in the need for iron. Negative pregnancy outcomes, such as increased maternal sickness, low birthweight, preterm, and intrauterine growth restriction, are linked to iron deficiency. IDA, or nutritional iron deficiency anemia, affects more than two billion people worldwide and is the most prevalent disease. Based on the regression-based analysis, the prevalence of anemia in the World Health Organization's global database was calculated to be 14%. According to recent data, there are 17.4% more IDA cases among pregnant women in industrialized countries than in poor ones (up to 56% more cases). Despite the fact that oral iron supplementation is frequently used to treat IDA, not all patients benefit from oral iron therapy. This is caused by a number of things, which include the adverse effects of oral iron, resulting in low compliance and ineffectiveness. In a sizable group of patients taking oral iron preparations, the adverse effects primarily include GI symptoms. Intravenous iron was previously underutilized since it was linked to unfavorable and occasionally dangerous side effects. New type II and III iron complexes have been created recently, though, and they offer superior compliance and toleration in addition to strong efficacy and a good safety profile.

Iron Metabolism in Normal and Pathological Pregnancies and Fetal Consequences

Iron is required for energy production, DNA synthesis, and cell proliferation, mainly as a component of the prosthetic group in hemoproteins and as part of iron-sulfur clusters. Iron is also a critical component of hemoglobin and plays an important role in oxygen delivery. Imbalances in iron metabolism negatively affect these vital functions. As the crucial barrier between the fetus and the mother, the placenta plays a pivotal role in iron metabolism during pregnancy. Iron deficiency affects 1.2 billion individuals worldwide. Pregnant women are at high risk of developing or worsening iron deficiency. On the contrary, in frequent hemoglobin diseases, such as sickle-cell disease and thalassemia, iron overload is observed. Both iron deficiency and iron overload can affect neonatal development. This review aims to provide an update on our current knowledge on iron and heme metabolism in normal and pathological pregnancies. The main molecular actors in human placental iron metabolism are described, focusing on the impact of iron deficiency and hemoglobin diseases on the placenta, together with normal metabolism. Then, we discuss data concerning iron metabolism in frequent pathological pregnancies to complete the picture, focusing on the most frequent diseases.