Iron Metabolism in African American Women in the Second and Third Trimesters of High-Risk Pregnancies

Objective: To examine iron metabolism during the second and third trimesters in African American women with high-risk pregnancies.

Design: Longitudinal pilot study.

Setting: Large, university-based, urban Midwestern U.S. medical center.

Participants: Convenience sample of 32 African American women with high-risk pregnancies seeking care at an urban maternal-fetal medicine clinic.

Methods: Nonfasting venous blood was collected in the second and third trimesters to assess iron status, hepcidin, and systemic inflammation. Anthropometric and survey data were obtained via self-report. Descriptive statistics were calculated from these data, and changes in the clinical parameters between the second and third trimesters were evaluated via paired t tests. Associations among demographic, reproductive, anthropometric, inflammatory, and iron-related parameters were also assessed in each trimester.

Results: The mean age of participants was 28.3 (± 6.8) years, and mean prepregnancy body mass index was 31.9 (± 10.7) kg/m². In the longitudinal analysis, significant (p < .05) declines in serum iron, ferritin, transferrin saturation, and C-reactive protein were observed between the second and third trimesters. There was no statistically significant change in hepcidin between trimesters. When using a ferritin level cut-point of less than 15 ng/ml and soluble transferrin receptor level of greater than 28.1 nmol/L, 48% of the participants (14 of 29) were classified with iron deficiency in the third trimester.

Conclusion: In this pilot study, iron deficiency was prevalent among a small cohort of African American women with high-risk pregnancies. Hepcidin concentrations were greater than previously reported in healthy, pregnant, primarily White women, which suggests decreased iron bioavailability in this high-risk group.