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

Abstract

Objective: The coexistence of underweight (UW) and overweight (OW)/obese (OB) at the population level is known to affect iron-deficiency anemia (IDA), but how the weight status affects erythropoiesis during pregnancy is less clear at a population scale. This study investigated associations between the pre-pregnancy body mass index (pBMI) and erythropoiesis-related nutritional deficiencies. Design: Anthropometry, blood biochemistry, and 24-h dietary recall data were collected during prenatal care visits. The weight status was defined based on the pBMI. Mild nutrition deficiency-related erythropoiesis was defined if individuals had an ID, folate depletion, or a vitamin B12 deficiency. Setting: The Nationwide Nutrition and Health Survey in Taiwan (Pregnant NAHSIT 2017-2019). Participants: We included 1456 women aged 20 to 45 years with singleton pregnancies. Results: Among these pregnant women, 9.6% were UW, and 29.2% were either OW (15.8%) or OB (13.4%). A U-shaped association between the pBMI and IDA was observed, with decreased odds (OR; 95% CI) for OW subjects (0.6; 0.4˜0.9) but increased odds for UW (1.2; 0.8˜2.0) and OB subjects (1.2; 0.8˜1.8). The pBMI was positively correlated with the prevalence of a mild nutritional deficiency. Compared to normal weight (NW), OB pregnant women had 3.4-fold (3.4; 1.4˜8.1) higher odds for multiple mild nutritional deficiencies, while UW individuals had lowest odds (0.3; 0.1-1.2). A dietary analysis showed negative relationships of pBMI with energy, carbohydrates, protein, iron, and folate intakes, but positive relationship with fat intakes. Conclusion: The pre-pregnancy weight status can possibly serve as a good nutritional screening tool for preventing IDA during pregnancy.

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

“…A population-scale cross-sectional survey, the Nationwide Nutrition and Health Survey in Taiwanese Pregnant Women (NAHSIT-PW), was conducted between 2017 and 2019. Details of the study design can be seen in previous publications [ 7 , 19 ]. Briefly, inclusion criteria were pregnant women aged ≥ 15 years, with Taiwanese residency who spoke fluent Chinese or Taiwanese, had received a maternal health checkout booklet, and for whom the legal guardian had a signed written informed agreement for those who were ≤19 years of age.…”

“…B 12 , respectively [ 5 ]. Deficiencies in erythropoiesis-related micronutrients may lead to the development of gestational anemia [ 6 ], including iron deficiency (ID) anemia (IDA) or megaloblastic anemia [ 7 ]. An insufficient iron supply can result in microcytic hypochromic anemia.…”

Iron Metabolism in Normal and Pathological Pregnancies and Fetal Consequences

“…Women with a pre-pregnancy body mass index > 30 kg/m 2 have a higher risk of developing iron-deficiency anemia during pregnancy. The BMI positively correlates with the concentration of soluble transferrin receptor (sTRf) and with that of serum iron, but not ferritin [138,139]. Indeed, obesity induces chronic low-grade inflammation and an elevated CRP concentration, as enlarged adipocytes tend to higher levels of pro-inflammatory cytokines, such as Il-6 [140][141][142][143].…”

Iron Deficiency Anemia in Pregnancy

“…However, if a hemoglobin level is below 100 g/L at any point in pregnancy, anemia should be investigated and treated due to the possibility of catastrophic effects for both the mother and her unborn child, including a higher risk of intrauterine growth retardation and premature birth. As a temporary measure, anemia in women of reproductive age is defined as Hb 120 g/L or, in some studies, 115 g/L [ 13 - 14 ].…”