Iron Status and Regulation in High‐Risk Pregnant African American Women

Abstract

Iron is essential across the lifecycle but is critical during pregnancy. African American (AA) women are more likely to be iron deficient (ID) during pregnancy and classified as having a high‐risk pregnancy due to factors including existing medical conditions and obesity. Such conditions can also compromise maternal iron metabolism due to inflammation‐induced overexpression of the iron‐regulatory peptide hormone hepcidin. The aim of this study was to examine iron status and regulation during the 2nd and 3rd trimester of pregnancy in AA women classified as a high‐risk pregnancy.MethodsNon‐fasting venous blood was drawn at 22 and 32 weeks gestation for the assessment of iron status, hepcidin, and inflammation. Anthropometric and survey data was also obtained. Ferritin < 15.0 and < 30.0 ng/ml (to account for inflammatory effects on ferritin) was used to define iron deficiency. Descriptive statistics were calculated and changes in the clinical parameters between the 2nd and 3rd trimester were evaluated via paired t‐test.ResultsForty seven women, mean age 28 (± 6.6) years and pre‐pregnancy BMI of 32.6 (± 11.6) kg/m2 were recruited. Mean habitual dietary iron intake was 38 mg/day. Between the 2nd and 3rd trimester, significant (p < 0.05) declines in serum iron, ferritin, transferrin saturation, hepcidin, and C‐reactive protein were observed. During the 2nd trimester, 28% of women were ID increasing to 50% in the 3rd trimester based on ferritin < 15.0 ng/ml. When using a ferritin cut‐point of < 30.0 ng/ml, 68% and 87% of women were classified as ID, respectively.ConclusionMaternal iron deficiency was prevalent among these high‐risk pregnant AA women. Although hepcidin declined significantly between trimesters, concentrations in this cohort were higher than previously reported in healthy pregnancy suggesting decreased maternal iron bioavailability. Because elevated maternal hepcidin may impair dietary iron absorption, further research is warranted in this high‐risk group.Support or Funding InformationCenter for Clinical and Translational Science (UL1RR029879) CCTS Pilot Grant Award, Award Number CCTS08011‐02