Iron Absorption and Requirements in Pregnancy and Lactation
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexFemale
Age18-45
SponsorUniversity of Oxford
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
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
Disqualifiers
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)
Trial 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.
Trial design
Design model
Cohort
Time perspective
Prospective
Treatments tested in this trial
CO-rebreathing
Other interventionIn 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
Oral iron isotope administration (54Fe)
Other interventionParticipants 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
Intravenous iron isotope administration (58Fe)
Other interventionParticipants randomly assigned to the sub-group, will receive intravenous 58Fe in the second and third trimester for assessment of erythrocyte iron incorporation
Treatment groups
250 Participants
are divided into 2 treatment groupsGroup A: All participants1 intervention
Group B: Randomly selected sub-group3 interventions
Trial outcomes
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 weeks2
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 weeks3
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 weeks4
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 weeksSecondary outcomes
1
Fractional iron absorption (%) in the second trimester
shift in iron isotopic ratios
Time frame
gestational age 20 weeks2
Fractional iron absorption (%) in the third trimester
shift in iron isotopic ratios
Time frame
gestational age 30 weeks3
Erythrocyte iron incorporation (%) in the second trimester
shift in iron isotopic ratios
Time frame
gestational age 20 weeks4
Erythrocyte iron incorporation (%) in the third trimester
shift in iron isotopic ratios
Time frame
gestational age 30 weeksSponsors and contacts
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University of Oxford
Lead sponsor
Columbia University
Collaborator
Jomo Kenyatta University of Agriculture and Technology
Collaborator
Msambweni County Referral Hospital
Collaborator
ETH Zurich
Collaborator
Source ClinicalTrials.gov