Adiposity and Iron Requirements in Pregnancy (ADIPREG)

June 30, 2026 updated by: University of Ulster

Impact of Maternal Adiposity on Maternal Iron Status and Requirements: a Randomised Intervention Study

This study aims to explore how body fat influences the response to either 25 or 50 mg of daily iron supplements during pregnancy. We will conduct a double-blind randomized controlled intervention study involving 312 pregnant women recruited from antenatal clinics in the Northern Trust Area. Participants will be randomly assigned to receive either 25 or 50 mg of iron per day from 12 weeks of pregnancy until delivery, using the Active Iron supplement brand. Blood samples will be collected at 12, 28 and 36 weeks gestation and umbilical cord blood will be collected at delivery. Anthropometric measurements will be taken at each visit, and participants will complete questionnaires on various aspects of health and lifestyle, mental health, gastrointestinal symptoms, and compliance.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The main aim of this study is to investigate the influence of adiposity on the difference in response to 25 or 50 mg of daily iron supplementation during pregnancy. The primary aim is to determine the influence of maternal adiposity on adjusted maternal ferritin concentrations in response to 25 mg or 50 mg iron supplementation in pregnancy. The secondary outcomes of this study include: investigating the impact of maternal body fat on various maternal iron biomarkers (such as haemoglobin, soluble transferrin receptor, hepcidin, transferrin saturation, and other haematological markers) in response to either 25 mg or 50 mg iron supplementation during pregnancy, evaluating changes in adjusted ferritin concentrations and other iron markers throughout pregnancy relative to the dosage of iron supplementation received, determining the effect of maternal body fat on neonatal iron biomarkers in response to maternal iron supplementation, assessing changes in markers of inflammation in response to iron supplementation during pregnancy, and examine changes in mental health scores in response to iron supplementation during pregnancy.

This is a double-blind randomised controlled intervention study, in which 312 pregnant women with singleton pregnancy, without current complications, aged ≥ 18 years and BMI ≥ 18.5 kg/m2 will be recruited. Participants who are taking multivitamins will be included. They will be asked to discontinue any current supplementation. Pregnant women with anaemia, iron deficiency, high risk of iron overload, history of bariatric surgery, who are planning home birth, are currently involved in another research study, and those who cannot speak or understand English language will be excluded.

Blood samples and anthropometric and body composition measurements will be taken at different points in the pregnancy (12, 28, 36 gestational weeks) and an umbilical cord blood sample at the time of birth. Blood concentrations of iron and inflammation markers will be analysed. General, dietary intake and lifestyle information will be collected, through a Health and Lifestyle questionnaire and a 4-day diary. Additionally, participants will complete a questionnaire about their mental health and gastrointestinal symptoms. The compliance of the supplementation will be evaluated at each timepoint. Additionally, participants will receive a telephone call to evaluate possible adverse effects and compliance of the supplementation between the timepoints (18, 24 and 32 weeks of gestation). In the event that a participant has been prescribed iron treatment, anaemia diagnosis at any time during pregnancy or the occurrence of any adverse outcome such as miscarriage, the participant will be withdrawn from the study. Electronic forms prepared in RedCap will be used to collect data.

Amendment to above protocol:

Removal of one of the exclusion criteria of the study: having a ferritin concentration < 30 ug/L at time of enrolment. Currently, ferritin is not part of routine investigations at any time during pregnancy, unless there are risk factors for iron deficiency (Pavord et al 2019).

Excluding pregnant women with low iron levels will select a very low risk population of developing iron deficiency, and therefore, they will not reflect the real effect of the intervention in this population.

2) Include an 8 week postpartum sampling timepoint. The intervention will conclude as originally planned during the delivery and will not be extended. An additional timepoint will be offered and explained to participants who are already enrolled, but they will not be obligated to participate.

Postpartum anemia affects 25-30% of women (Bodnar et al., 2005). Additionally, recent unpublished data from Northern Ireland shows that 80% of women receiving 17 mg/day of iron supplementation throughout pregnancy were iron deficient by 36 weeks, with even higher rates among pregnant women with obesity. Given these findings, we will extend our assessment of iron status after the intervention by adding this postpartum timepoint.

Study Type

Interventional

Enrollment (Estimated)

312

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United Kingdom
    • Co Londonderry
      • Coleraine, Co Londonderry, United Kingdom, BT52 1HS
    • Co. Londonderry
      • Coleraine, Co. Londonderry, United Kingdom, BT521SA
        • Recruiting
        • Ulster University,Human Intervention Studies Unit,
        • Contact:
        • Contact:
      • Coleraine, Co. Londonderry, United Kingdom, BT52 1HS

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:- Pregnant women

  • Age ≥ 18 years
  • BMI ≥18.5 kg/m2
  • Without current pregnancy complications (for example, severe bleeding, Diabetes Mellitus, hyperemesis gravidarum, ectopic and molar pregnancies)
  • At least 12 Gestational Week
  • Singleton pregnancy confirmed with the first ultrasound scan
  • Participants who are currently taking multivitamins will be included. They will be asked to discontinue any current supplementation.

Exclusion Criteria:

  • Hb <110 g/L
  • SF <30 μg/L
  • High risk of iron overload (Hb >150 g/L, transferrin saturation >45% or SF> 150 μg/L)
  • Participants with history of haematological, renal, liver, autoimmune disorders, malabsorptive syndromes
  • Participants with history of bariatric surgery
  • Participants who take steroids or anti-inflammatory treatments or drugs that affect gut absorption (proton-pump inhibitors)
  • Planned home births
  • Participants currently involved in another research study
  • Multiple pregnancy
  • Participants who do not speak English

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Iron 25
Iron 25 (total 25 mg/d of iron): 2 supplements of 12.5 mg of elemental iron + 1 multivitamin supplement;
Dietary supplement: Adiposity and Iron Requirements in Pregnancy (ADIPREG)

Iron 25 arm will receive: two iron supplements containing 12.5 mg of elemental iron + 1 multivitamin supplement (they will receive a total of 3 supplements per day).

Iron 50 arm will receive: two 25 mg elemental iron supplements + 1 multivitamin supplement (they will receive a total of 3 supplements per day).

The multivitamin supplement will contain folic acid, vitamin B1, vitamin B2, vitamin B3, vitamin B5, vitamin B6, vitamin B12, vitamin C and vitamin D. In summary, each participant will receive 3 supplements per day and instructed to take the 3 supplements together, in the morning, with breakfast. Supplements will be given to the participants when they attend for their clinic appointment. The intervention will begin at 12 gestational weeks and continue until the baby is delivered.
Active Comparator: IRON 50
Iron 50 (total 50 mg/d of iron): 2 supplements of 25 mg of elemental iron + 1 multivitamin supplement).
Dietary supplement: Adiposity and Iron Requirements in Pregnancy (ADIPREG)

Iron 25 arm will receive: two iron supplements containing 12.5 mg of elemental iron + 1 multivitamin supplement (they will receive a total of 3 supplements per day).

Iron 50 arm will receive: two 25 mg elemental iron supplements + 1 multivitamin supplement (they will receive a total of 3 supplements per day).

The multivitamin supplement will contain folic acid, vitamin B1, vitamin B2, vitamin B3, vitamin B5, vitamin B6, vitamin B12, vitamin C and vitamin D. In summary, each participant will receive 3 supplements per day and instructed to take the 3 supplements together, in the morning, with breakfast. Supplements will be given to the participants when they attend for their clinic appointment. The intervention will begin at 12 gestational weeks and continue until the baby is delivered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
* - Adjusted maternal ferritin concentrations in response to iron supplementation (ng/mL)
Time Frame: 16, 24 and 28 weeks after baseline
Assessed via electrochemiluminescence immunoassay "ECLIA".
16, 24 and 28 weeks after baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Hemoglobin (g/L)
Time Frame: 16, 24 and 28 weeks after baseline
Assessed via Direct Current sheat flow method (Sysmex)
16, 24 and 28 weeks after baseline
Red blood cell count (RBC) (10^12/L)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via Direct Current sheat flow method (Sysmex)
16, 24 and 28 weeks after baseline.
Mean cell haemoglobin (MCH) (pg
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via Direct Current sheat flow method (Sysmex)
16, 24 and 28 weeks after baseline.
Mean cell volume (MCV) (fl)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via Direct Current sheat flow method (Sysmex)
16, 24 and 28 weeks after baseline.
Mean cell haemoglobin concentrations (MCHC) (g/dL)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via Direct Current sheat flow method (Sysmex)
16, 24 and 28 weeks after baseline.
Red cell distribution width (RDW) (%)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via Direct Current sheat flow method (Sysmex)
16, 24 and 28 weeks after baseline.
Transferrin (g/L)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via immunoturbidimety assay
16, 24 and 28 weeks after baseline.
Serum iron (umol/L)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via colorimetic assay
16, 24 and 28 weeks after baseline.
sTfR (ug/mL)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via ELISA
16, 24 and 28 weeks after baseline.
Hepcidin (pg/mL)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via ELISA
16, 24 and 28 weeks after baseline.
C-reactive protein (mg/mL)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via ELISA
16, 24 and 28 weeks after baseline.
Pro- anti- inflammatory biomarkers: IL-1 β, IL-6, IL-10, IL-22, IL-17, TNF- α, IFN- γ (fg/mL)
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via sandwich immunoassay
16, 24 and 28 weeks after baseline.
Genetic variants of interest in relation to obesity and iron metabolism in response to iron supplementation.
Time Frame: 16, 24 and 28 weeks after baseline.
Assessed via methylation analyses
16, 24 and 28 weeks after baseline.
Mental health score in response to iron supplementation
Time Frame: 16, 24 and 28 weeks after baseline
CORE 10 questionnaire will be completed by each participant at each timepoint: CORE stands for "Clinical Outcomes in Routine Evaluation." The CORE-10 is a 10-item assesses psychological distress over the past week. The resulting score can be divided into categories with increasing severity: Healthy (0-5), low (6-10), mild (11-14), moderate (15-19), moderate-to-severe (20-24), and severe (25 and above). The score of this questionnaire will be collected as a numeric variable.
16, 24 and 28 weeks after baseline

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Adjusted maternal ferritin concentrations in response to iron supplementation (ng/mL)
Time Frame: 16, 24 and 28 weeks after baseline
Assessed via ELISA analyses for ferritin concentration
16, 24 and 28 weeks after baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Ulster

Collaborators

National Health Service, United Kingdom
Solvotrin Therapeutics - Active Iron

Investigators

  • Study Director: Mary McCann, PhD, University of Ulster

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 20, 2024

Primary Completion (Estimated)

January 19, 2027

Study Completion (Estimated)

March 19, 2027

Study Registration Dates

First Submitted

May 9, 2024

First Submitted That Met QC Criteria

May 21, 2024

First Posted (Actual)

May 22, 2024

Study Record Updates

Last Update Posted (Actual)

July 1, 2026

Last Update Submitted That Met QC Criteria

June 30, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FCBMS-23-259

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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