Table 4

Trimester-specific odds ratios (OR)* of low birth weight and premature birth for pollution exposure

Pollutant
Low birth weight
Preterm birth



Single pollutant model
Multiple pollutant model†
Single pollutant model
Multiple pollutant model†



OR (95% CI)
OR (95% CI)
OR 95% CI
OR 95% CI

Formaldehyde(per 5 μg/m3 increase in concentration)

1st trimester
2.20 (1.00–4.85)
2.39 (1.07–5.32)
1.13 (0.64–1.97)
0.91 (0.49–1.68)
2nd trimester
1.48 (0.65–3.40)
1.57 (0.68–3.64)
0.46 (0.27–0.78)
0.38 (0.21–0.67)
3rd trimester
1.29 (0.62–2.73)
1.17 (0.52–2.65)
1.01 (0.64–1.59)
0.94 (0.57–1.53)

NO2 (per 10 μg/m3 increase in concentration)

1st trimester
0.91 (0.53–1.56)
0.79 (0.45–1.39)
1.67 (1.28–2.18)
1.69 (1.28–2.23)
2nd trimester
0.93 (0.61–1.41)
0.88 (0.57–1.36)
1.13 (0.90–1.40)
1.30 (1.03–1.64)
3rd trimester
1.34 (0.94–1.92)
1.32 (0.92–1.91)
1.19 (0.96–1.47)
1.19 (0.96–1.49)

* odds ratio adjusted for gestational age (low birth weight model only), parity, maternal age (≤ 19, 20–29, 30–34, ≥ 35), marital status, education, season of birth, maternal and paternal smoking † also adjusted for the other air pollutant assessed

Maroziene and Grazuleviciene Environmental Health: A Global Access Science Source 2002 1:6   doi:10.1186/1476-069X-1-6