Table 4 Maternal air pollution exposure during total pregnancy according to infant characteristics

Child characteristics

Gestational age at birth

< 37 weeks

463

30.4 (3.3)

40.0 (4.5)

37-42 weeks (Reference)

6871

30.2 (3.1)

39.7 (4.2)

< 42 weeks

556

30.1 (3.3)

39.7 (4.1)

Birth weight

< 2500 grams

359

30.4 (3.1)

40.0 (4.4)

2500-4500 grams (Reference)

7194

30.2 (3.2)

39.7 (4.2)

> 4500 grams

337

30.0 (3.2)

39.6 (4.3)

Season of birth

Winter (Reference)

1856

29.7 (2.7)

38.9 (4.1)

Spring

1781

30.4 (2.3) **

41.0 (3.8) **

Summer

2098

30.5 (3.4) **

40.4 (4.0) **

Fall

2155

30.0 (3.8)

38.7 (4.5)

Year of birth

2002 (Reference)

696

33.6 (1.7)

39.6 (3.5)

2003

2406

33.2 (1.6) **

41.9 (3.9) **

2004

2548

27.6 (2.4) **

39.0 (4.2) *

2005

2214

28.8 (1.5) **

38.3 (3.9) **

2006

26

27.8 (1.3) **

36.8 (4.1) *