Table 2 Distribution of maternal characteristics in the first and last years of the series and AAPC^a of low birth weight among single newborns for each stratum of the variables studied, Brazil and its regions according to the 26 state capitals and Brazil’s capital, Brasília, between 1996 and 2011

 10–17 years

14.9

11.3

-

-

11.4

9.0

-

-

8.0

7.0

-

-

 ≥35 years

4.7

8.6

-

-

6.4

10.9

-

-

9.7

15.3

-

-

 18-34

80.3

80.0

-

-

82.2

80.2

-

-

82.2

77.7

-

-

 LBW 10–17 years

10.2

10.6

0.1 (−0.9;1.2)

<0.001

9.9

10.7

0.2 (−0.5;0.9)

0.037

11.9

10.9

−0.5 (−1.5;0.4)

0.227

 LBW ≥35 years

6.6

8.6

1.8 (1.0;2.6)^a

<0.001

7.7

9.0

0.6 (0.2;1.1)^a

<0.001

11.0

9.3

−0.9 (−1.1;−0.6)^a

<0.001

 LBW 18–34

6.0

7.0

1.1 (0.5;1.8)^a

<0.001

6.6

7.4

0.8 (0.5;1.1)^a

<0.001

8.3

7.6

−0.4 (−1.2;0.4)

0.001

 <8 years

64.2

28.3

-

-

62.3

26.2

-

-

48.9

19.5

-

-

 ≥12

3.0

16.4

-

-

5.5

19.5

-

-

10.4

24.5

-

-

 8–11

32.7

55.3

-

-

32.2

54.3

-

-

40.7

56.0

-

-

 LBW <8 years

7.1

8.3

1.2 (0.6;1.9)^a

<0.001

7.7

9.0

1.1 (0.7;1.5)^a

<0.001

10.0

9.7

−0.2 (−1.1;0.7)

<0.001

 LBW ≥12

5.4

7.5

3.2 (1.3;5.0)^a

<0.001

5.1

7.3

1.3 (0.6;2)^a

<0.001

5.7

7.2

1.5 (1.0;2.1)^a

<0.001

 LBW 8-11

5.7

7.2

1.6 (1.3;2.0)^a

<0.001

6.2

7.5

1.4 (0.7;2.2)^a

<0.001

7.9

8.0

0.1 (−1.3;1.5)

<0.001

 None

11.1

4.1

-

-

9.7

4.7

-

-

6.6

1.7

-

-

 ≤6 or

35.5

49.9

-

-

37.5

46.9

-

-

35.1

24.2

-

-

 ≥7

53.4

46.0

-

-

52.8

48.4

-

-

58.3

74.1

-

-

 LBW None

10.1

13.9

2.7 (−0.2;5.6)

<0.001

11.3

13.2

1.5 (−0.5;3.6)

<0.001

16.9

24.2

3.7 (2.7;4.7)^a

<0.001

 LBW ≤6 or

7.5

9.3

1.3 (0.9;1.8)^a

<0.001

8.4

9.8

1 (0.1;1.8)^a

<0.001

11.7

14.0

1.4 (0.4;2.3)^a

<0.001

 LBW ≥7

5.4

5.0

−0.4 (−0.8;0.1)

0.002

5.1

5.2

0.4 (−0.2;0.9)

<0.001

6.1

5.8

−0.3 (−0.5;0.0)^a

<0.001

 <37

4.9

10.8

-

-

4.9

11.0

-

-

6.5

8.7

-

-

 ≥37

95.1

89.2

-

-

95.1

89.0

-

-

93.5

91.3

-

-

 LBW <37

45.1

34.9

1.2 (−1.6;4)

<0.001

48.1

39.4

−1.2 (−3.7;1.3)

<0.001

59.3

52.5

−0.1 (−0.6;0.4)

<0.001

 LBW ≥37

4.6

4.2

0.1 (−0.7;0.8)

0.937

4.8

3.7

−1.3 (−2.2;0.4)^a

<0.001

5.2

3.9

−2 (−2.7;1.3)^a

<0.001

 Caesarean section

34.5

51.2

-

-

38.0

60.3

-

-

47.3

53.1

-

-

 Vaginal delivery

65.5

48.8

-

-

62.0

39.7

-

-

52.7

46.9

-

-

 Caesarean section LBW

5.3

7.4

2.1 (1.4;2.8)^a

<0.001

5.8

7.1

1.2 (0.7;1.7)^a

<0.001

8.0

8.4

0.5 (−0.1;1.1)

<0.001

 Vaginal delivery LBW

7.3

7.7

0.4 (0.0;0.9)

<0.001

7.7

9.0

0.7 (0.4;1.1)^a

<0.001

9.6

7.8

−1.2 (−1.5;−0.9)^a

<0.001

 10–17 years

9.4

6.7

-

-

10.6

7.0

-

-

10.1

8.1

-

-

 ≥35 years

10.5

15.4

-

-

5.9

12.3

-

-

8.0

13.1

-

-

 18-34

80.1

77.9

-

-

83.5

80.6

-

-

81.9

78.9

-

-

 LBW 10–17 years

10.6

10.0

−0.3 (−1.1;0.5)

0.246

10.2

10.3

0.6 (0.1;1.0)^a

0.001

11.0

10.8

−0.1 (−0.8;0.5)^a

0.008

 LBW ≥35 years

9.2

8.8

−0.5 (−1;−0.1)^a

0.010

8.9

8.6

0.3 (−0.3;0.8)

0.175

9.8

9.1

−0.4 (−0.6;−0.2)

<0.001

 LBW 18–34

6.8

7.5

0.5 (0.0;1.1)

<0.001

6.7

7.7

0.9 (0.5;1.2)^a

<0.001

7.4

7.5

0.1 (−0.4;0.6)

<0.001

 <8 years

46.2

20.6

-

-

52.6

18.8

-

-

55.4

22.3

-

-

 ≥12

10.8

33

-

-

7.4

27.0

-

-

7.2

22.9

-

-

 8–11

42.9

46.4

-

-

40.1

54.2

-

-

37.4

54.8

-

-

 LBW <8 years

8.6

9.5

1 (0.4;1.6)

<0.001

7.9

9.2

0.7 (0.2;1.2)^a

<0.001

8.4

9.3

0.6 (−1;2.2)

,0.001

 LBW ≥

5.2

6.8

1.8 (0.7;2.9)^a

<0.001

5.7

7.8

1.8 (1.2;2.3)^a

<0.001

5.6

7.3

1.5 (1.1;1.9)^a

,0.001

 LBW 8-11

6.6

7.8

1.1 (0.1;2.2)^a

<0.001

6.5

7.6

1.2 (0.7;1.6)^a

<0.001

6.9

7.8

0.9 (0.6;1.1)^a

<0.001

 None

4.4

1.4

-

-

5.5

3.3

-

-

8.3

3.0

-

-

 ≤6 or UD

32.5

17.7

-

-

40.1

27.6

-

-

35.8

33.5

-

-

 ≥7

63.2

80.9

-

-

54.5

69.2

-

-

55.9

63.5

-

-

 LBW None

16.5

24.6

3.1 (1.4;4.8)^a

<0.001

13.5

16.9

1.3 (−1.4;4.1)

<0.001

12.9

17.4

2.4 (0.6;4.1)^a

<0.001

 LBW ≤6 or UD

9.7

15.3

3.2 (2.4;4.0)^a

<0.001

8.2

12.3

2.6 (2.1;3.1)^a

<0.001

9.3

11.5

1.3 (0.2;2.4)^a

<0.001

 LBW ≥7

5.5

5.9

0.4 (−0.1;0.8)

0.011

5.9

5.7

0.3 (−0.2;0.8)

0.004

5.8

5.6

−0.1 (−0.3;0.0)

0.002

 <37

5.5

8.2

-

-

3.9

9.7

-

-

5.2

9.6

-

-

 ≥37

94.5

91.8

-

-

96.1

90.3

-

-

94.8

90.4

-

-

LBW <37

63.1

57.4

−0.5 (−0.8;−0.2)

<0.001

62.1

44.9

0 (−1.7;1.8)

0.019

56.1

46.1

−1 (−2.3;0.3)

<0.001

 LBW ≥37

4.1

3.4

−1.4 (−1.8;−0.9)^a

<0.001

4.9

4.0

−0.7 (−2.7;1.3)

<0.001

4.9

3.9

−1.6 (−2.1;−1.1)^a

<0.001

 Caesarean section

44.2

56.6

-

-

49.2

59.5

-

-

42.9

55.2

-

-

 Vaginal delivery

55.8

43.4

-

-

50.8

40.5

-

-

57.1

44.8

-

-

 Caesarean section LBW

7.3

8.4

0.5 (0.0;1.1)^a

<0.001

6.3

8.0

1.6 (1.2;2.0)^a

<0.001

7.1

8.0

1 (0.6;1.4)^a

<0.001

 Vaginal delivery LBW

7.5

7.1

−0.2 (−0.6;0.2)

0.078

8.1

8.0

0 (−0.4;0.5)

0.929

8.6

8.0

−0.5 (−1.1;0.2)

<0.001