Neonatal iron status is impaired by maternal obesity and excessive weight gain during pregnancy

Phillips AK¹, Roy SC², Lundberg R², Guilbert TW¹, Auger AP³, Blohowiak SE¹, Coe CL⁴, Kling PJ¹.

Author information

^{1 – School of Medicine and Public Health, and Meriter Hospital, University of Wisconsin, Madison, WI, USA}
^{2 – Department of Pediatrics, University of Wisconsin, Madison, WI, USA.}
^{3 – Department of Psychology, University of Wisconsin, Madison, WI, USA.}
^{4 – Harlow Center for Biological Psychology, University of Wisconsin, Madison, WI, USA.}

Abstract

OBJECTIVE: Maternal iron needs increase sixfold during pregnancy, but obesity interferes with iron absorption. We hypothesized that maternal obesity impairs fetal iron status.

STUDY DESIGN: Three hundred and sixteen newborns with risk factors for infantile iron deficiency anemia (IDA) were studied to examine obesity during pregnancy and neonatal iron status. Erythrocyte iron was assessed by cord blood hemoglobin (Hb), zinc protoporphyrin/heme (ZnPP/H) and reticulocyte-ZnPP/H, and storage iron by serum ferritin.

RESULT: Women with body mass index (BMI) ⩾ 30 kg m(-)(2), as compared with non-obese women, delivered larger offspring with higher reticulocyte-ZnPP/H and lower serum ferritin concentrations (P<0.05 for both). With increasing BMI, the estimated body iron was relatively lower (mg kg(-)(1)) and the ratio of total Hb-bound iron (mg) per total body iron (mg) increased. Maternal diabetes compromised infant iron status, but multivariate analysis demonstrated that obesity was an independent predictor.

CONCLUSION: Obesity during pregnancy and excessive weight gain are independent risk factors for iron deficiency in the newborn.