Daily Versus Alternate-Day Oral Iron Therapy for Anemia in Second-Trimester Pregnancy

June 14, 2026 updated by: Ammara Suleman, Pakistan Air Force (PAF) Hospital Islamabad

Daily Versus Alternate-Day Oral Iron Therapy for Anemia Correction in Second-Trimester Pregnant Patients: A Randomized Controlled Trial

This randomized controlled trial compares daily versus alternate-day oral iron supplementation in pregnant women with iron deficiency anemia during the second trimester. The study evaluates changes in hemoglobin and serum ferritin, treatment adherence, and gastrointestinal side effects to inform more patient-centered, physiologically aligned dosing strategies.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Iron deficiency anemia is the leading cause of anemia in pregnancy. Although daily oral iron is standard first-line therapy, it is frequently associated with gastrointestinal side effects and poor adherence. Because hepcidin rises after an iron dose and remains elevated for 24 to 48 hours, daily dosing may reduce fractional absorption; alternate-day dosing allows hepcidin to fall between doses, potentially improving absorption and tolerance.

This single-center, prospective, randomized, parallel-group trial will recruit pregnant women (13 to 27 weeks gestation) with hemoglobin below 11 g/dL and serum ferritin below 30 ng/mL from the antenatal clinic at PAF Teaching Hospital, Islamabad. Eligible, consenting participants will be randomized 1:1 to daily ferrous sulfate (one 325 mg tablet, approximately 65 mg elemental iron, once daily) or alternate-day ferrous sulfate (two 325 mg tablets, approximately 130 mg elemental iron, every other day) for four weeks.

The primary outcome is change in hemoglobin from baseline to Week 4. Secondary outcomes are change in serum ferritin, treatment adherence (proportion taking at least 80 percent of doses, by pill count and diary), and the frequency and severity of gastrointestinal side effects. Outcome assessors (laboratory personnel) are blinded to allocation; participant blinding is not feasible given the differing dosing schedules. Planned enrollment is 184 participants (92 per group), giving 90 percent power to detect a 0.40 g/dL difference in hemoglobin change at a two-sided alpha of 0.05, assuming a standard deviation of 0.83 g/dL.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
184

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Pakistan
      • Islamabad, Pakistan
        • Pakistan Air Force (PAF) Hospital Islamabad

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged 18 to 40 years
  • Pregnant women in the second trimester (13 to 27 weeks gestation)
  • Hemoglobin below 11 g/dL with serum ferritin below 30 ng/mL
  • Singleton pregnancy

Exclusion Criteria:

  • Known congenital or acquired hemoglobin disorders (e.g., thalassemia, hemoglobinopathies)
  • Chronic diseases affecting hemoglobin levels (e.g., chronic kidney disease, inflammatory disorders)
  • Bleeding disorders or a history of frequent blood loss
  • Gastrointestinal conditions impairing nutrient absorption (e.g., celiac disease or other malabsorption syndromes)
  • Currently receiving parenteral iron
  • Requiring blood transfusion

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Daily Iron
One ferrous sulfate 325 mg tablet (approximately 65 mg elemental iron) once daily for four weeks.
Drug: Ferrous Sulfate
Oral ferrous sulfate 325 mg tablets (approximately 65 mg elemental iron per tablet) administered for four weeks according to the assigned dosing schedule. All participants receive standardized counseling on administration, diet, side effects, and adherence, and are issued a dose diary.
Experimental: Alternate-Day Iron
Two ferrous sulfate 325 mg tablets (approximately 130 mg elemental iron) every other day for four weeks.
Drug: Ferrous Sulfate
Oral ferrous sulfate 325 mg tablets (approximately 65 mg elemental iron per tablet) administered for four weeks according to the assigned dosing schedule. All participants receive standardized counseling on administration, diet, side effects, and adherence, and are issued a dose diary.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in hemoglobin from baseline to Week 4
Time Frame: Baseline and Week 4
Mean within-participant change in hemoglobin concentration (g/dL), measured at baseline and at Week 4, compared between the daily and alternate-day arms.
Baseline and Week 4

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in serum ferritin from baseline to Week 4
Time Frame: Baseline and Week 4
Mean within-participant change in serum ferritin concentration (ng/mL) from baseline to Week 4, compared between groups.
Baseline and Week 4
Treatment adherence
Time Frame: Through Week 4
Proportion of participants taking at least 80 percent of prescribed doses, determined by pill count cross-checked against patient dose diaries.
Through Week 4
Frequency of gastrointestinal side effects
Time Frame: Through Week 4
Proportion of participants reporting any gastrointestinal side effect (nausea, vomiting, constipation, metallic taste, or abdominal discomfort) recorded using a structured checklist.
Through Week 4
Severity of gastrointestinal side effects
Time Frame: Through Week 4
Severity of reported gastrointestinal side effects graded as mild, moderate, or severe on a structured checklist.
Through Week 4

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Pakistan Air Force (PAF) Hospital Islamabad

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ammara Suleman, MBBS, Pakistan Air Force (PAF) Hospital Islamabad

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 14, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 14, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 18, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRON-DvA-2026-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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