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NCT Number: NCT03206710

Vitamin C Supplementation to Pregnant Smokers: Follow-up of 2 Randomized Trials Plus Changes in DNA Methylation

In a randomized clinical trial (RCT) published in JAMA, the investigators have provided evidence that vitamin C supplementation (500 mg daily during pregnancy) ameliorates the effects of maternal smoking during pregnancy on offspring lung function and subsequent incidence of wheeze by 48% through 1 year of age. The investigators are currently completing a second RCT of vitamin C supplementation in pregnant smokers with more robust measures of pulmonary outcomes. The purpose of this ECHO application is to combine these 2 focused, interventional cohorts to allow critical longitudinal follow-up of respiratory outcomes in these children including the study of pulmonary function test (PFT) trajectories and incidence of recurrent wheeze/asthma from infancy through early adolescence in offspring of pregnant smokers randomized to vitamin C versus placebo.

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Key information

Conditions

Asthma Bronchial Diseases Hypersensitivity Hypersensitivity, Immediate Immune System Diseases In Utero Nicotine Lung Diseases Lung Diseases, Obstructive Pathological Conditions, Signs and Symptoms Pulmonary Function Respiratory Hypersensitivity Respiratory Sounds Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory Wheezing

Age range

6 month–11 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Indiana University, Indianapolis, Indiana, United States

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About this study

In a randomized clinical trial (RCT) published in JAMA, the investigators have provided evidence that vitamin C supplementation (500 mg daily during pregnancy) ameliorates the effects of maternal smoking during pregnancy on offspring lung function and subsequent incidence of wheeze by 48% through 1 year of age. the investigators are currently completing a second RCT of vitamin C supplementation in pregnant smokers with more robust measures of pulmonary outcomes. The purpose of this ECHO application is to combine these 2 focused, interventional cohorts to allow critical longitudinal follow-up of respiratory outcomes in these children including the study of pulmonary function test (PFT) trajectories and incidence of recurrent wheeze/asthma from infancy through early adolescence in offspring of pregnant smokers randomized to vitamin C versus placebo.

This will allow the investigators to study the duration of the protection vitamin C provides in the face of in-utero smoke, the relationship between PFTs and the development of recurrent wheeze and/or asthma. In addition we have preliminary data suggesting that, in parallel with the effects of vitamin C on the reduction of pulmonary harm, the supplementary vitamin C blocked the majority of significant changes in DNA methylation induced by maternal smoking in placentas, cord blood and offspring cheek cells. Thus this study will also study the association between the prevention of wheeze/asthma associated with maternal smoking during pregnancy and the prevention of epigenetic changes caused by maternal smoking during pregnancy. By linking the clinical outcomes of decreased wheeze/asthma and pulmonary function in offspring of smokers to epigenetic changes, this study has the potential to identify genes linked to the effects of maternal smoking on lung development and the protective effects of vitamin C.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Women and their offspring randomized to vitamin C versus placebo during pregnancy in VCSIP1 or VCSIP2 as well as pregnant nonsmokers and their offspring enrolled as the reference group in VCSIP 1 or VCSIP2

Exclusion criteria

  • Patients specifically withdrawing consent from VCSIP1 or VCSIP2

Treatment and study plan

No current intervention

Other

This is a follow-up of two randomized trials. No active intervention is being given in the follow-up

Primary outcomes

  1. Improved pulmonary function

    Time frame: through 15 years of age

    The first primary aim of this study is to demonstrate improved pulmonary function trajectories as measured with forced expiratory flows through 15 years of age in the offspring of pregnant smokers randomized to vitamin C (500 mg/day) versus placebo.

  2. Decreased recurrent wheeze/asthma

    Time frame: through 15 years of age

    The second primary aim of this study is to demonstrate a decreased incidence of recurrent wheeze/ asthma through 15 years of age in the offspring of pregnant smokers randomized to vitamin C (500 mg/day) versus placebo.

Secondary outcomes

  1. Decreased incidence of recurrent wheeze/asthma

    Time frame: through 15 years of age

    A secondary aim of this study is to demonstrate a decreased incidence of recurrent wheeze/asthma through 15 years of age in offspring of pregnant smokers randomized to vitamin C (500 mg/day) versus placebo

  2. Epigenetic changes

    Time frame: through 15 years of age

    An additional secondary aim of the study is the analysis of epigenetic changes caused by maternal smoking and reversed by vitamin C at birth. DNA methylation will be measured in biologic samples and then followed longitudinally through ages 15.

Sponsors and collaborators

Lead sponsor

Oregon Health and Science University

Other

Collaborators

  • Indiana University
  • National Institutes of Health (NIH)

Registry information

Official study title

Maternal Vitamin C Supplementation to Decrease Effects of Smoking During Pregnancy on Infant Lung Function and Health: Follow-up of 2 Randomized Trials and Association With Changes in DNA Methylation

Acronym: VCSIP-ECHO

Important dates

Study start
2017
Primary completion
2023
Study completion
2024
First posted
Jul 2, 2017
Registry last updated
Mar 21, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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