Evaluating the Effects of Supplemental Vitamin C on Infant Lung Function in Pregnant Smoking Women

Pregnancy Clinical Trial

Official title:

In-Utero Smoke, Vitamin C, and Newborn Lung Function

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00632476
• Other study ID #: 546
• Secondary ID: K23HL080231K23HL
• Status: Completed
• Phase: N/A
• First received: March 5, 2008
• Last updated: August 31, 2013
• Start date: March 2007
• Est. completion date: July 2012

Study information

• Verified date: August 2013
• Source: Oregon Health and Science University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Interventional

Clinical Trial Summary

Women who smoke during their pregnancy place their unborn child at an increased risk of health problems, including decreased lung function and possible lung diseases later in life. Preliminary animal research suggests that if vitamin C is taken during pregnancy, nicotine's harmful effects on the unborn baby's developing lungs may be blocked. This study will determine the effect that vitamin C has on the lung development and function of babies born to women who smoke during pregnancy.

Description:

Approximately 12% of women smoke during pregnancy, and at least 500,000 babies are born each year having been exposed to nicotine. These infants have poor lung function at birth and have an increased risk of developing lung diseases, including bronchitis, pneumonia, and asthma. Researchers believe that nicotine may interact with nicotinic receptors in the unborn child's developing lungs and cause altered growth and decreased lung function. Preliminary animal research studies suggest that some of the harmful effects of nicotine may be blocked by vitamin C, an antioxidant that may protect against cellular damage caused by nicotine and other pollutants. The purpose of this study is to evaluate the effectiveness of vitamin C at blocking the harmful effects of nicotine exposure on lung development and function in children born to women who smoke during pregnancy.

This study will enroll pregnant women who smoke, as well as a control group of pregnant women who do not smoke. At a baseline study visit, all participants will complete smoking history questionnaires. For 2 weeks, all participants who smoke will receive placebo capsules once a day. They will then be randomly assigned to receive either vitamin C capsules or placebo capsules, both of which will be taken once a day, in addition to a prenatal vitamin, for the duration of their pregnancy. Study visits, occurring once a month throughout the pregnancy, will include a medical and smoking history review and urine collection. An ultrasound exam will be performed once during the pregnancy to determine the exact size and age of the baby, and blood collection will occur at baseline and once or twice more during the pregnancy. Study researchers will review participants' medical records and will call participants three times during their pregnancy to review their food intake. At the time of delivery, amniotic fluid samples will be collected. When babies are 48 hours old, baby lung function testing will occur, and when babies are 3 and 9 months of age, researchers will call participants to collect breathing information on the babies. When babies are 12 months old, participants will attend a study visit that will include urine collection from the babies and a review of baby breathing difficulties, medication changes, and environmental smoking exposure.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 282
• Est. completion date: July 2012
• Est. primary completion date: July 2011
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 15 Years and older

Eligibility

Inclusion Criteria:

• Randomly assigned to a study intervention at less than 22 weeks of gestation

• History of smoking

• Singleton gestation pregnancy

• Smoking cessation intervention offered but declined

Exclusion Criteria:

• Multiple gestation pregnancy

• Documented major fetal congenital anomalies

• History of kidney stones

• Insulin dependent diabetes

• Current participation in other research projects that may interfere with this study

• Continuous use of high dose vitamin C since last menstrual period (LMP) or initial ascorbic acid level greater than 100 micromoles/liter

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Pregnancy
• Smoking

Intervention

Other:
• Placebo
Placebo capsule once a day

Dietary Supplement:
• Vitamin C
A 500-mg vitamin C capsule once a day

Locations

Country	Name	City	State
United States	Oregon Health & Science University	Portland	Oregon

Sponsors (3)

Lead Sponsor	Collaborator
Oregon Health and Science University	National Heart, Lung, and Blood Institute (NHLBI), National Institute of Environmental Health Sciences (NIEHS)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Pulmonary function testing (including respiratory compliance and the ratio of time to peak tidal expiratory flow to total expiratory time)		Measured within 48 hours after delivery	No
Secondary	Pulmonary function testing (including respiratory compliance and the ratio of time to peak tidal expiratory flow to total expiratory time)and respiratory history including wheezing through 12 months of age.		Measured at 12 months of age	No