Iron Absorption and Requirements in Pregnancy and Lactation

Recruiting

• Conditions: Iron Absorption; Iron Requirements; Pregnancy; Lactation; Infancy

• 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

Study Timeline

• Status Verified: 2023-06
• Study First Submitted: 2023-07-18
• Study Start: 2023-07-31
• Study First Submitted QC: 2023-07-31
• Last Update Submitted: 2023-07-31
• Study First Posted: 2023-08-03
• Last Update Posted: 2023-08-03
• Primary Completion: 2026-06-30
• Study Completion: 2026-09-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 250

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

• 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

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
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
Serum ferritin concentration (ug/l)	age 24 weeks	infant
Soluble transferrin receptor concentration (ul/l)	age 24 weeks	infant
Intestinal fatty acid binding protein	gestational age 30 weeks	I-FABP
Fibroblast growth factor 21	gestational age 30 weeks	FGF21
Blood volume (l)	24 weeks postpartum	BV
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

Trial Locations

Locations (1)

Msambweni Referral Hospital; 🇰🇪 Msambweni, Kenya