Elsevier

The Journal of Nutrition

Volume 145, Issue 8, August 2015, Pages 1916-1923
The Journal of Nutrition

Prenatal Iron Supplementation Reduces Maternal Anemia, Iron Deficiency, and Iron Deficiency Anemia in a Randomized Clinical Trial in Rural China, but Iron Deficiency Remains Widespread in Mothers and Neonates1, 2, 3

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Abstract

Background: Previous trials of prenatal iron supplementation had limited measures of maternal or neonatal iron status.

Objective: The purpose was to assess effects of prenatal iron-folate supplementation on maternal and neonatal iron status.

Methods: Enrollment occurred June 2009 through December 2011 in Hebei, China. Women with uncomplicated singleton pregnancies at ≤20 wk gestation, aged ≥18 y, and with hemoglobin ≥100 g/L were randomly assigned 1:1 to receive daily iron (300 mg ferrous sulfate) or placebo + 0.40 mg folate from enrollment to birth. Iron status was assessed in maternal venous blood (at enrollment and at or near term) and cord blood. Primary outcomes were as follows: 1) maternal iron deficiency (ID) defined in 2 ways as serum ferritin (SF) <15 μg/L and body iron (BI) <0 mg/kg; 2) maternal ID anemia [ID + anemia (IDA); hemoglobin <110 g/L]; and 3) neonatal ID (cord blood ferritin <75 μg/L or zinc protoporphyrin/heme >118 μmol/mol).

Results: A total of 2371 women were randomly assigned, with outcomes for 1632 women or neonates (809 placebo/folate, 823 iron/folate; 1579 mother-newborn pairs, 37 mothers, 16 neonates). Most infants (97%) were born at term. At or near term, maternal hemoglobin was significantly higher (+5.56 g/L) for iron vs. placebo groups. Anemia risk was reduced (RR: 0.53; 95% CI: 0.43, 0.66), as were risks of ID (RR: 0.74; 95% CI: 0.69, 0.79 by SF; RR: 0.65; 95% CI: 0.59, 0.71 by BI) and IDA (RR: 0.49; 95% CI: 0.38, 0.62 by SF; RR: 0.51; 95% CI: 0.40, 0.65 by BI). Most women still had ID (66.8% by SF, 54.7% by BI). Adverse effects, all minor, were similar by group. There were no differences in cord blood iron measures; >45% of neonates in each group had ID. However, dose-response analyses showed higher cord SF with more maternal iron capsules reported being consumed (β per 10 capsules = 2.60, P < 0.05).

Conclusions: Prenatal iron supplementation reduced anemia, ID, and IDA in pregnant women in rural China, but most women and >45% of neonates had ID, regardless of supplementation. This trial was registered at clinicaltrials.gov as NCT02221752.

Keywords

pregnant women
neonates
iron supplementation
iron deficiency
iron deficiency anemia
randomized clinical trial

Abbreviations

BI
body iron
CRP
C-reactive protein
ID
iron deficiency
IDA
iron deficiency anemia
MCHC
Maternity and Child Health Care Center
MCV
mean corpuscular volume
SF
serum ferritin
sTfR
serum transferrin receptor
ZPP/H
zinc protoporphyrin/heme

Cited by (0)

1

The pregnancy study was supported by a grant from Vifor Pharma Ltd. (GZ, Principal Investigator). The laboratory measures of iron status were supported by a grant from the NIH (R01 HD052069; BL, Principal Investigator), which included funding from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Office of Dietary Supplements.

2

Author disclosures: G Zhao, G Xu, M Zhou, Y Jiang, B Richards, KM Clark, N Kaciroti, MK Georgieff, Z Zhang, T Tardif, M Li, and B Lozoff, no conflicts of interest.

3

The content is solely the responsibility of the authors and does not necessarily represent the official views of Vifor Pharma or the NIH. The authors had full control of primary data and did not have an agreement with the funders that limited their ability to complete the research as planned.