Iron Absorption and Requirements in Pregnancy and Lactation
- Conditions
- Iron AbsorptionIron RequirementsPregnancyLactationInfancy
- Interventions
- Other: CO-rebreathingOther: Oral iron isotope administration (54Fe)Other: Intravenous iron isotope administration (58Fe)
- Registration Number
- NCT05973552
- Lead Sponsor
- University of Oxford
- Brief 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.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- Female
- Target Recruitment
- 250
- 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
- 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)
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Arm && Interventions
Group Intervention Description Randomly selected sub-group CO-rebreathing 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. Randomly selected sub-group Oral iron isotope administration (54Fe) 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. All participants CO-rebreathing 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. Randomly selected sub-group Intravenous iron isotope administration (58Fe) 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.
- Primary Outcome Measures
Name Time Method Iron absorbed, lossed and gained in infancy Change in 57Fe tracer abundance between age 6, 14 and 24 weeks isotope dilution
Iron absorbed, lossed and gained in the first trimester Change in 57Fe tracer abundance between gestational age 6, 10 and 15 weeks isotope dilution
Iron absorbed, lossed and gained in the second trimester Change in 57Fe tracer abundance between gestational age 15, 20 and 25 weeks isotope dilution
Iron absorbed, lossed and gained in the third trimester Change in 57Fe tracer abundance between gestational age 25, 30 and 35 weeks isotope dilution
Iron absorbed, lossed and gained throughout pregnancy Change in 57Fe tracer abundance between gestational age 6, 10, 15, 20, 25, 30 and 35 weeks isotope dilution
Iron absorbed, lossed and gained in lactating women Change in 57Fe tracer abundance between 6, 14 and 24 weeks postpartum isotope dilution
- Secondary Outcome Measures
Name Time Method Mean corpuscular volume (fl) age 24 weeks infant
Serum ferritin concentration (ug/l) age 24 weeks infant
Blood volume (l) 24 weeks postpartum BV
Erythrocyte iron incorporation (%) in the second trimester gestational age 20 weeks shift in iron isotopic ratios
Fractional iron absorption (%) in the second trimester gestational age 20 weeks shift in iron isotopic ratios
Fractional iron absorption (%) in the third trimester gestational age 30 weeks shift in iron isotopic ratios
Erythroferrone concentration (ng/ml) 24 weeks postpartum ERFE
C-reactive protein concentration (mg/l) age 24 weeks infant
alpha-glycoprotein concentration (mg/dl) age 24 weeks infant
Erythrocyte iron incorporation (%) in the third trimester gestational age 30 weeks shift in iron isotopic ratios
Hemoglobin concentration (g/dl) age 24 weeks infant
Erythropoietin concentration (mU/ml) 24 weeks postpartum EPO
Hepcidin concentration (ng/ml) 24 weeks postpartum Hep
Soluble transferrin receptor concentration (ul/l) age 24 weeks infant
Intestinal fatty acid binding protein gestational age 30 weeks I-FABP
Retinol binding protein gestational age 30 weeks RBP
Insulin-like growth factor 1 gestational age 30 weeks IGF-1
soluble CD14 gestational age 30 weeks sCD14
Fibroblast growth factor 21 gestational age 30 weeks FGF21
Trial Locations
- Locations (1)
Msambweni Referral Hospital
🇰🇪Msambweni, Kenya