VCSIP Follow-up Study

Completed

• Conditions: Pulmonary Function; In Utero Nicotine; Asthma; Wheezing
• Interventions: Other: No active intervention

• Registration Number: NCT03203603
• Lead Sponsor: Oregon Health and Science University

Brief Summary

The overall aims of this protocol are to determine whether prenatal supplementation with vitamin C to pregnant smokers can improve pulmonary function and decrease wheeze at 5 years of age in their offspring. This is a continuation of the VCSIP trial, to follow the offspring through 5 years of age. The hypothesis for this protocol is an extension of the VCSIP trial that supplemental vitamin C in pregnant smokers can significantly improve their children's PFTs and decrease the incidence of wheeze.

Detailed Description

The overall aims of this protocol are to determine whether prenatal supplementation with vitamin C to pregnant smokers can improve pulmonary function and decrease wheeze at 5 years of age in their offspring. This is a continuation of the VCSIP trial, to follow the offspring through 5 years of age. The hypothesis for this protocol is an extension of the VCSIP trial that supplemental vitamin C in pregnant smokers can significantly improve their children's PFTs and decrease the incidence of wheeze. The reasons for this protocol are to follow the children born to mothers randomized in the VCSIP to the age of 5 to differentiate the patients with transient versus recurrent wheeze (and therefore more likely to develop asthma); to determine if early protective effects of vitamin C are sustained to this older age; and to continue to collect biologic samples from the children for future mechanistic studies of vitamin C action.

The primary aim of this study is to demonstrate improved pulmonary function at 5 years of age in the offspring of pregnant smokers randomized to vitamin C (500 mg/day) versus placebo. The investigators hypothesize that vitamin C supplementation in pregnancy will block the adverse effects of maternal smoking on offspring pulmonary function measured at 5 years of age by spirometry. Impulse oscillometry (IOS) will also be used at 3-5 years of age to assess pulmonary function.

Specific Aim 2 (Secondary Outcome): The secondary aim of this study is to demonstrate a decreased incidence of wheeze at 5 years of age in offspring of pregnant smokers randomized to vitamin C (500 mg/day) versus placebo. The investigators hypothesize that vitamin C supplementation during pregnancy will decrease the incidence of wheeze at 5 years of age in offspring of smokers. Respiratory health will be assessed by quarterly validated respiratory questionnaires and clinician report.

Study Timeline

• Study Start: 2017-03-27
• Study First Submitted: 2017-03-28
• Study First Submitted QC: 2017-06-27
• Study First Posted: 2017-06-29
• Primary Completion: 2021-12-31
• Study Completion: 2024-12-31
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-20
• Last Update Posted: 2025-03-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 242

Inclusion Criteria

• Women and their offspring randomized to vitamin C versus placebo during pregnancy as well as pregnant nonsmokers and their offspring enrolled as the reference group in the current RCT.

Exclusion Criteria

• Patients specifically withdrawing consent.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Offspring of smokers who got vitamin C	No active intervention	Offspring of pregnant smokers randomized to vitamin C during the initial randomized portion of the VCSIP study
Offspring of smokers who got placebo	No active intervention	Offspring of pregnant smokers randomized to placebo during the initial randomized portion of the VCSIP study
Offspring of pregnant non-smokers	No active intervention	Offspring of pregnant non-smokers who were followed in a similar fashion during pregnancy as the randomized pregnant smokers

Primary Outcome Measures

Name	Time	Method
Improved pulmonary function, spirometry	5 years of age	The primary aim of this study is to demonstrate improved pulmonary function at 5 years of age in the offspring of pregnant smokers randomized to vitamin C 500 mg/day versus placebo.

Secondary Outcome Measures

Name	Time	Method
Decreased incidence of wheeze	5 years of age	The secondary aim of this study is to demonstrate a decreased incidence of wheeze at 5 year of age in offspring of pregnant smokers randomized to vitamin C (500 mg/day) versus placebo

Trial Locations

Locations (2)

Indiana University; 🇺🇸 Indianapolis, Indiana, United States

Oregon Health and Science University; 🇺🇸 Portland, Oregon, United States