Abstract

BACKGROUND

The knowledge about air pollution effects on birth weight, prematurity, and small for gestational age (SGA) in low-exposure areas is insufficient.Maternal Exposure

OBJECTIVES:

The aim of this birth cohort study was to investigate whether low-level exposure to air pollution was associated with prematurity and fetal growth and whether there are sex-specific effects.Maternal Exposure

METHOD:

We combined high-quality registry information on 81,110 births with individually modeled exposure data at residence for nitrogen oxides (NO(x)) and proximity to roads with differing traffic density. The data were analyzed by logistic and linear regression with and without potential confounders.Maternal Exposure

RESULTS:

We observed an increased risk for babies being SGA when we compared highest and lowest NO(x) quartiles, adjusting for maternal age, smoking, sex, and year of birth. After additional adjustment for maternal country of origin and parity (which were highly intercorrelated), the increase was no longer statistically significant. However, in subgroup analyses when we compared highest and lowest NO(x) quartiles we still observed an increased risk for SGA for girls [odds ratio (OR)=1.12; 95% confidence interval (CI), 1.01-1.24); we also observed increased risk among mothers who had not changed residency during pregnancy (OR=1.09; 95% CI, 1.01-1.18). The confounders with the greatest impact on SGA were parity and country of origin. Concerning prematurity, the prevalence was lower in the three higher NO(x) exposure quartiles compared with the lowest category.Maternal Exposure

TABLE OF CONTENTS

Cover Page – – – – – – – – – –

Title Page – – – – – – – – – –

Certification – – – – – – – – – –

Dedication – – – – – – – – – –

Acknowledgement – – – – – – – – –

Abstract – – – – – – – – – –

Table of Content – – – – – – – – –

Chapter One: Introduction

Background of the Study – – – – – –

Statement of the Problem – – – – – –

Objectives of the Study – – – – – – –

Research Questions – – – – – – –

Research Hypotheses – – – – – – –

Significance of the Study – – – – – – –

Scope/ Limitation of the Study – – – – – –

Definition of Terms – – – – – – –

Chapter Two: Review of Related Literature

2.1 Introduction – – – – – – – – –

2.2 Conceptual Framework – – – – – – –

2.3 Theoretical Framework – – – – – – –

2.4 Empirical Review – – – – – – – –

Chapter Three: Research Methodology

3.1 Introduction – – – – – – – –

3.1 Research Design – – – – – – – –

3.3 Area of the Study – – – – – – – –

3.4 Population of the Study – – – – – – –

3.5 Sample Size and Sampling Techniques – – – –

3.6 Instrumentation – – – – – – – –

3.7 Validation of the Instrument – – – – – –

3.8 Administration of the Instrument – – – – –

3.9 Method of Data Analysis – – – – – – –

Chapter Four: Presentation, Analysis and Interpretation of Data

4.1 Introduction – – – – – – – – –

4.2 Presentation and Analysis of Data – – – – –

4.3 Testing of Hypotheses – – – – – – –

4.4 Discussion of Findings – – – – – – –

Chapter Five: Summary, Conclusion and Recommendations

5.1 Introduction – – – – – – – – –

5.2 Summary – – – – – – – – –

5.3 Conclusion – – – – – – – – –