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RecruitingNCT05973552PILLAR_IIUpdated Aug 3, 2023

Iron Absorption and Requirements in Pregnancy and Lactation

An observational study in Iron Requirements, Pregnancy and Lactation, sponsored by University of Oxford. Recruiting at 1 site in Kenya. Open to female participants aged 18 Years to 45 Years. Per ClinicalTrials.gov, last updated 2023-08-03.

Sponsored by University of Oxford · Observational

From the registry’s dates

  • Primary completion was expected by Jun 2026, 3 months ago, but the record still lists the study as recruiting.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
250
Ages
18 Years to 45 Years
Sex
Female
01

Study summary

Iron requirements increase significantly during pregnancy. Current recommendations for iron intake in pregnant and lactating women (PLW) are mainly based on factorial estimates and extrapolated from non-PLW. High-quality quantitative data on iron requirements in PLW are lacking, particularly in Sub- Saharan Africa where anaemia and infections are common.

The primary objective of this study is to use the stable iron isotope technique to determine iron requirements and assess iron absorption and losses in PLW living in Kenya.

In this prospective observational study, we will enrol pregnant women in the first trimester (n = 250) from a previous study cohort (n=1000) who participated in an iron absorption study at least 12 months ago and received the stable iron (Fe) isotope 57Fe. This 57Fe has now distributed and equilibrated throughout the women's body iron. Once enrolled in the present study, following Kenyan guidelines, women will receive standard prenatal care, including routine daily iron and folate supplementation. We will collect venous blood samples in each trimester and at delivery, and during the first 6 months of lactation in the mothers and infants (heel prick samples). To directly assess dietary iron absorption, in a randomly selected subset of women (n=35), oral and intravenous stable iron isotope tracers (54Fe, 58Fe) will be administered in the 2nd and 3rd trimesters.

02

Conditions studied

  • Iron Requirements
  • Pregnancy
  • Lactation
  • Infancy
  • Iron Absorption
03

In context

Lead sponsor

University of Oxford is the lead sponsor of 794 studies on the registry; 117 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 45 Years
Sexes eligible
Female
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

This study will recruit 250 pregnant women in the first trimester who previously participated in a stable iron isotope study (Clinical Trial ID: NCT05266703) and received 15 mg of the stable iron isotope 57Fe as an oral dose of ferrous sulphate at least 12 months before being enrolled in this trial.

Inclusion criteria

  • Providing consent to the informed consent form
  • Participation in a previous stable isotope absorption study and having received an oral dose of 15 mg 57Fe at least 12 months prior to the date of inclusion in the study
  • Positive pregnancy test and gestational age \<10 weeks based on history of last menstrual period
  • Permanent residence in the study area, and not expected to leave the study site for more than 4 weeks over the following 16 months
  • Assessment of good health by professional staff at Msambweni Hospital

Exclusion criteria

Exclusion Criteria:

  • Pre-pregnancy body mass index >30 kg/m2
  • Blood transfusion or intravenous iron treatment within 4 months of study start
  • Major chronic infectious disease (e.g., tuberculosis, HIV+, hepatitis)
  • Major chronic non-infectious disease (e.g., Type 1 or 2 diabetes, cancer)
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
250 participants (estimated)
Patient registry
No

Groups and cohorts

  • All participants

    Women (n=250), are followed throughout their pregnancy. Mother-infant pairs are followed throughout the first 6-months postpartum. Women receive daily oral iron supplementation during pregnancy in accordance with local standards of care. Using the stable iron isotopes dilution methodology, concentration of the stable iron isotope tracer (57Fe) in circulation will be measured throughout pregnancy and up to 6 months postpartum in both, mother and infant.

    Other: CO-rebreathing

  • Randomly selected sub-group

    To directly assess dietary iron absorption, in a randomly selected subset of women (n=35), oral and intravenous stable iron isotope tracers (54Fe, 58Fe) will be administered. Oral iron absorption and erythrocyte iron incorporation will be measured 14 days after tracer administration.

    Other: CO-rebreathing · Other: Oral iron isotope administration (54Fe) · Other: Intravenous iron isotope administration (58Fe)

Interventions

  • OtherCO-rebreathing

    In the CO-rebreathing method, a dedicated apparatus is used for inhaling and rebreathing a very small bolus of CO through a spirometer for \~2 min, which is absorbed through the lungs and binds to Hb, and then the increase of HbCO content of blood is measured 8 min after the CO inhalation. The increase of COHb in blood samples can then be used to precisely calculate Hb mass and blood volume

  • OtherOral iron isotope administration (54Fe)

    Participants randomly assigned to the sub-group, will receive 54Fe with a test meal in the second and third trimester for assessment of dietary iron absorption

  • OtherIntravenous iron isotope administration (58Fe)

    Participants randomly assigned to the sub-group, will receive intravenous 58Fe in the second and third trimester for assessment of erythrocyte iron incorporation

06

What researchers measure

Primary outcomes

  1. Iron absorbed, lossed and gained in the first trimester

    isotope dilution

    Time frame: Change in 57Fe tracer abundance between gestational age 6, 10 and 15 weeks

  2. Iron absorbed, lossed and gained in the second trimester

    isotope dilution

    Time frame: Change in 57Fe tracer abundance between gestational age 15, 20 and 25 weeks

  3. Iron absorbed, lossed and gained in the third trimester

    isotope dilution

    Time frame: Change in 57Fe tracer abundance between gestational age 25, 30 and 35 weeks

  4. Iron absorbed, lossed and gained throughout pregnancy

    isotope dilution

    Time frame: Change in 57Fe tracer abundance between gestational age 6, 10, 15, 20, 25, 30 and 35 weeks

  5. Iron absorbed, lossed and gained in lactating women

    isotope dilution

    Time frame: Change in 57Fe tracer abundance between 6, 14 and 24 weeks postpartum

  6. Iron absorbed, lossed and gained in infancy

    isotope dilution

    Time frame: Change in 57Fe tracer abundance between age 6, 14 and 24 weeks

Secondary outcomes

  1. Fractional iron absorption (%) in the second trimester

    shift in iron isotopic ratios

    Time frame: gestational age 20 weeks

  2. Fractional iron absorption (%) in the third trimester

    shift in iron isotopic ratios

    Time frame: gestational age 30 weeks

  3. Erythrocyte iron incorporation (%) in the second trimester

    shift in iron isotopic ratios

    Time frame: gestational age 20 weeks

  4. Erythrocyte iron incorporation (%) in the third trimester

    shift in iron isotopic ratios

    Time frame: gestational age 30 weeks

  5. Hemoglobin concentration (g/dl)

    Hb

    Time frame: gestational age 6 weeks

  6. Hemoglobin concentration (g/dl)

    Hb

    Time frame: gestational age 10 weeks

  7. Hemoglobin concentration (g/dl)

    Hb

    Time frame: gestational age 15 weeks

  8. Hemoglobin concentration (g/dl)

    Hb

    Time frame: gestational age 20 weeks

  9. Hemoglobin concentration (g/dl)

    Hb

    Time frame: gestational age 25 weeks

  10. Hemoglobin concentration (g/dl)

    Hb

    Time frame: gestational age 30 weeks

  11. Hemoglobin concentration (g/dl)

    Hb

    Time frame: gestational age 36 weeks

  12. Hemoglobin concentration (g/dl)

    mother

    Time frame: 6 weeks postpartum

  13. Hemoglobin concentration (g/dl)

    infant

    Time frame: age 6 weeks

  14. Hemoglobin concentration (g/dl)

    mother

    Time frame: 14 weeks postpartum

  15. Hemoglobin concentration (g/dl)

    infant

    Time frame: age 14 weeks

  16. Hemoglobin concentration (g/dl)

    mother

    Time frame: 24 weeks postpartum

  17. Hemoglobin concentration (g/dl)

    infant

    Time frame: age 24 weeks

  18. Mean corpuscular volume (fl)

    MCV

    Time frame: gestational age 6 weeks

  19. Mean corpuscular volume (fl)

    MCV

    Time frame: gestational age 10 weeks

  20. Mean corpuscular volume (fl)

    MCV

    Time frame: gestational age 20 weeks

  21. Mean corpuscular volume (fl)

    MCV

    Time frame: gestational age 30 weeks

  22. Mean corpuscular volume (fl)

    mother

    Time frame: 6 weeks postpartum

  23. Mean corpuscular volume (fl)

    infant

    Time frame: age 6 weeks

  24. Mean corpuscular volume (fl)

    mother

    Time frame: 14 weeks postpartum

  25. Mean corpuscular volume (fl)

    infant

    Time frame: age 14 weeks

  26. Mean corpuscular volume (fl)

    mother

    Time frame: 24 weeks postpartum

  27. Mean corpuscular volume (fl)

    infant

    Time frame: age 24 weeks

  28. Erythropoietin concentration (mU/ml)

    EPO

    Time frame: gestational age 10 weeks

  29. Erythropoietin concentration (mU/ml)

    EPO

    Time frame: gestational age 20 weeks

  30. Erythropoietin concentration (mU/ml)

    EPO

    Time frame: gestational age 30 weeks

  31. Erythropoietin concentration (mU/ml)

    EPO

    Time frame: 6 weeks postpartum

  32. Erythropoietin concentration (mU/ml)

    EPO

    Time frame: 14 weeks postpartum

  33. Erythropoietin concentration (mU/ml)

    EPO

    Time frame: 24 weeks postpartum

  34. Erythroferrone concentration (ng/ml)

    ERFE

    Time frame: gestational age 10 weeks

  35. Erythroferrone concentration (ng/ml)

    ERFE

    Time frame: gestational age 20 weeks

  36. Erythroferrone concentration (ng/ml)

    ERFE

    Time frame: gestational age 30 weeks

  37. Erythroferrone concentration (ng/ml)

    ERFE

    Time frame: 6 weeks postpartum

  38. Erythroferrone concentration (ng/ml)

    ERFE

    Time frame: 14 weeks postpartum

  39. Erythroferrone concentration (ng/ml)

    ERFE

    Time frame: 24 weeks postpartum

  40. Hepcidin concentration (ng/ml)

    Hep

    Time frame: gestational age 10 weeks

  41. Hepcidin concentration (ng/ml)

    Hep

    Time frame: gestational age 20 weeks

  42. Hepcidin concentration (ng/ml)

    Hep

    Time frame: gestational age 30 weeks

  43. Hepcidin concentration (ng/ml)

    Hep

    Time frame: 6 weeks postpartum

  44. Hepcidin concentration (ng/ml)

    Hep

    Time frame: 14 weeks postpartum

  45. Hepcidin concentration (ng/ml)

    Hep

    Time frame: 24 weeks postpartum

  46. Serum ferritin concentration (ug/l)

    SF

    Time frame: gestational age 10 weeks

  47. Serum ferritin concentration (ug/l)

    SF

    Time frame: gestational age 20 weeks

  48. Serum ferritin concentration (ug/l)

    SF

    Time frame: gestational age 30 weeks

  49. Serum ferritin concentration (ug/l)

    mother

    Time frame: 6 weeks postpartum

  50. Serum ferritin concentration (ug/l)

    infant

    Time frame: age 6 weeks

  51. Serum ferritin concentration (ug/l)

    mother

    Time frame: 14 weeks postpartum

  52. Serum ferritin concentration (ug/l)

    infant

    Time frame: age 14 weeks

  53. Serum ferritin concentration (ug/l)

    mother

    Time frame: 24 weeks postpartum

  54. Serum ferritin concentration (ug/l)

    infant

    Time frame: age 24 weeks

  55. Soluble transferrin receptor concentration (ul/l)

    sTfR

    Time frame: gestational age 10 weeks

  56. Soluble transferrin receptor concentration (ul/l)

    sTfR

    Time frame: gestational age 20 weeks

  57. Soluble transferrin receptor concentration (ul/l)

    sTfR

    Time frame: gestational age 30 weeks

  58. Soluble transferrin receptor concentration (ul/l)

    mother

    Time frame: 6 weeks postpartum

  59. Soluble transferrin receptor concentration (ul/l)

    infant

    Time frame: age 6 weeks

  60. Soluble transferrin receptor concentration (ul/l)

    mother

    Time frame: 14 weeks postpartum

  61. Soluble transferrin receptor concentration (ul/l)

    infant

    Time frame: age 14 weeks

  62. Soluble transferrin receptor concentration (ul/l)

    mother

    Time frame: 24 weeks postpartum

  63. Soluble transferrin receptor concentration (ul/l)

    infant

    Time frame: age 24 weeks

  64. C-reactive protein concentration (mg/l)

    CRP

    Time frame: gestational age 10 weeks

  65. C-reactive protein concentration (mg/l)

    CRP

    Time frame: gestational age 20 weeks

  66. C-reactive protein concentration (mg/l)

    CRP

    Time frame: gestational age 30 weeks

  67. C-reactive protein concentration (mg/l)

    mother

    Time frame: 6 weeks postpartum

  68. C-reactive protein concentration (mg/l)

    infant

    Time frame: age 6 weeks

  69. C-reactive protein concentration (mg/l)

    mother

    Time frame: 14 weeks postpartum

  70. C-reactive protein concentration (mg/l)

    infant

    Time frame: age 14 weeks

  71. C-reactive protein concentration (mg/l)

    mother

    Time frame: 24 weeks postpartum

  72. C-reactive protein concentration (mg/l)

    infant

    Time frame: age 24 weeks

  73. alpha-glycoprotein concentration (mg/dl)

    AGP

    Time frame: gestational age 10 weeks

  74. alpha-glycoprotein concentration (mg/dl)

    AGP

    Time frame: gestational age 20 weeks

  75. alpha-glycoprotein concentration (mg/dl)

    AGP

    Time frame: gestational age 30 weeks

  76. alpha-glycoprotein concentration (mg/dl)

    mother

    Time frame: 6 weeks postpartum

  77. alpha-glycoprotein concentration (mg/dl)

    infant

    Time frame: age 6 weeks

  78. alpha-glycoprotein concentration (mg/dl)

    mother

    Time frame: 14 weeks postpartum

  79. alpha-glycoprotein concentration (mg/dl)

    infant

    Time frame: age 14 weeks

  80. alpha-glycoprotein concentration (mg/dl)

    mother

    Time frame: 24 weeks postpartum

  81. alpha-glycoprotein concentration (mg/dl)

    infant

    Time frame: age 24 weeks

  82. Blood volume (l)

    Time frame: gestational age 10 weeks

  83. Blood volume (l)

    BV

    Time frame: gestational age 20 weeks

  84. Blood volume (l)

    BV

    Time frame: gestational age 30 weeks

  85. Blood volume (l)

    BV

    Time frame: 6 weeks postpartum

  86. Blood volume (l)

    BV

    Time frame: 14 weeks postpartum

  87. Blood volume (l)

    BV

    Time frame: 24 weeks postpartum

  88. Intestinal fatty acid binding protein

    I-FABP

    Time frame: gestational age 10 weeks

  89. Intestinal fatty acid binding protein

    I-FABP

    Time frame: gestational age 20 weeks

  90. Intestinal fatty acid binding protein

    I-FABP

    Time frame: gestational age 30 weeks

  91. Retinol binding protein

    RBP

    Time frame: gestational age 10 weeks

  92. Retinol binding protein

    RBP

    Time frame: gestational age 20 weeks

  93. Retinol binding protein

    RBP

    Time frame: gestational age 30 weeks

  94. soluble CD14

    sCD14

    Time frame: gestational age 10 weeks

  95. soluble CD14

    sCD14

    Time frame: gestational age 20 weeks

  96. soluble CD14

    sCD14

    Time frame: gestational age 30 weeks

  97. Insulin-like growth factor 1

    IGF-1

    Time frame: gestational age 10 weeks

  98. Insulin-like growth factor 1

    IGF-1

    Time frame: gestational age 20 weeks

  99. Insulin-like growth factor 1

    IGF-1

    Time frame: gestational age 30 weeks

  100. Fibroblast growth factor 21

    FGF21

    Time frame: gestational age 10 weeks

  101. Fibroblast growth factor 21

    FGF21

    Time frame: gestational age 20 weeks

  102. Fibroblast growth factor 21

    FGF21

    Time frame: gestational age 30 weeks

07

Study locations

1 of 1 sites recruiting
  • Msambweni Referral Hospital
    Msambweni, Kenya
    • Edith Mwasi, MD · Contact
    Recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 3, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05973552
Lead sponsor
University of Oxford
Collaborators
Columbia University, Jomo Kenyatta University of Agriculture and Technology, Msambweni County Referral Hospital, ETH Zurich
Responsible party
Sponsor
First posted
Aug 3, 2023
Start date
Jul 31, 2023 (estimated)
Primary completion
Jun 30, 2026 (estimated)
Completion
Sep 1, 2026 (estimated)
Last update
Aug 3, 2023

Study contacts

Nicole Stoffel, PhD
Contact
nicole.stoffel@rdm.ox.ac.uk
+41446328393
Joyce Wali, BSc
Contact
stellawali507@gmail.com
+254704862877

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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