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A Randomized Air Filter Intervention Study of Air Pollution and Fetal Growth in a Highly Polluted Community

This study has been completed.
Canadian Institutes of Health Research (CIHR)
Information provided by (Responsible Party):
Ryan Allen, Simon Fraser University Identifier:
First received: November 30, 2012
Last updated: December 1, 2016
Last verified: April 2015
The purpose of this study is to use an air filter intervention to evaluate the relationship between particulate matter air pollution exposure during pregnancy and fetal growth. We hypothesize that: 1) portable high efficiency air (HEPA) filters will produce major reductions in home indoor concentrations of particulate matter and 2) pregnant women whose exposures to particulate matter are reduced by this intervention will give birth to children with greater mean body weight for gestational age.

Condition Intervention
Fetal Growth Restriction Device: HEPA Filter

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: A Randomized Air Filter Intervention Study of Air Pollution and Fetal Growth in a Highly Polluted Community

Resource links provided by NLM:

Further study details as provided by Ryan Allen, Simon Fraser University:

Primary Outcome Measures:
  • Gestational-age adjusted birthweight [ Time Frame: At birth ]
  • Birthweight [ Time Frame: At birth ]
  • Gestational age [ Time Frame: At birth ]
  • Head circumference [ Time Frame: At birth ]
  • Small for gestational age [ Time Frame: At birth ]
    <10%ile of birth weight for gestational age

  • Birth length [ Time Frame: At birth ]
    Birth length

Secondary Outcome Measures:
  • Blood pressure [ Time Frame: At approximately 10, 11, 30 and 31 weeks gestation ]
  • C-reactive protein [ Time Frame: At approximately 10 and 30 weeks gestation ]
  • Stratified Analyses [ Time Frame: Various ]
    For all variables, we will explore effect modification by maternal exposure to environmental tobacco smoke, fraction of time spent at home, sex of the baby, season of birth, gestational age at birth, and the fraction of time that the HEPA filter(s) were used.

Enrollment: 540
Study Start Date: January 2014
Study Completion Date: December 2015
Primary Completion Date: December 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: HEPA Filter
HEPA filter(s) placed in the participant's home from approximately 10 weeks gestation until birth.
Device: HEPA Filter
No Intervention: Control


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Adult (>18 years)
  • Pregnant woman in first trimester (<14 weeks)
  • Single gestation pregnancy
  • Non-smoker

Exclusion Criteria:

  • Multiple-gestation pregnancy
  • Current smoker
  • Currently operating an air filter in the home
  • Currently living in a ger (traditional Mongolian felt-lined yurt)
  • Plan to give birth outside of a hospital or clinic in Ulaanbaatar
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Please refer to this study by its identifier: NCT01741051

Mongolia National University of Medical Sciences
Ulaanbaatar, Mongolia
Sponsors and Collaborators
Simon Fraser University
Canadian Institutes of Health Research (CIHR)
Principal Investigator: Ryan Allen, PhD Simon Fraser University
  More Information

Responsible Party: Ryan Allen, Associate Professor, Simon Fraser University Identifier: NCT01741051     History of Changes
Other Study ID Numbers: 275997
Study First Received: November 30, 2012
Last Updated: December 1, 2016

Keywords provided by Ryan Allen, Simon Fraser University:
Air pollution
Particulate matter
Intrauterine growth restriction (IUGR)
Fetal growth
Birth weight
Gestational age

Additional relevant MeSH terms:
Fetal Growth Retardation
Fetal Diseases
Pregnancy Complications
Growth Disorders
Pathologic Processes processed this record on September 19, 2017