Table 2 Odds Ratios (95% confidence intervals) for factors related to VLBW in East and West Berlin^*

previous preterm delivery

no

157

69

3.70 (1.47–9.33)

0.006

161

72

1.92 (0.85–4.35)

0.120

yes

8

13

14

12

previous fetal loss

no

106

41

1.77 (1.03–3.02)

0.038

112

39

2.05 (1.21–3.48)

0.008

yes

60

41

63

45

previous induced abortion

no

130

58

1.49 (0.82–2.73)

0.191

139

58

1.73 (0.96–3.12)

0.068

yes

36

24

36

26

assisted reproduction

no

163

79

1.38 (0.23–8.40)

0.730

164

77

1.49 (0.55–4.07)

0.435

yes

3

2

10

7

prima para

no

82

40

1.03 (0.60–1.74)

0.927

90

37

1.35 (0.80–2.27)

0.267

yes

84

42

85

47

low net income

no

164

76

6.47 (1.28–32.8)

0.024

171

78

3.29 (0.90–11.00)

0.071

yes

2

6

4

6

single mother status

no

139

56

2.39 (1.28–4.45)

0.006

167

67

5.30 (2.18–12.90)

< 0.001

yes

27

26

8

17

low maternal education^**

no

141

53

3.09 (1.66–5.74)

< 0.001

130

46

2.39 (1.38–4.13)

0.002

yes

25

29

45

38

single-room apartment

no

151

67

2.25 (1.04–4.87)

0.039

169

75

3.38 (1.16–9.84)

0.025

yes

15

15

6

9

maternal unemployment

no

133

53

2.21 (1.22–4.00)

0.009

163

70

2.72 (1.20–6.17)

0.017

yes

33

29

12

14

migrant from developing country

no

154

71

1.99 (0.84–4.72)

0.119

143

62

1.59 (0.86–2.95)

0.145

yes

12

11

32

22

maternal age < 20 years

no

157

75

1.63 (0.58–4.54)

0.351

172

80

2.87 (0.63–13.10)

0.175

yes

9

7

3

4

maternal age > 35 years

no

155

73

1.74 (0.69–4.38)

0.241

149

68

1.35 (0.68–2.68)

0.393

yes

11

9

26

16

body mass index < 20

no

108

54

0.88 (0.50–1.56)

0.654

131

64

0.86 (0.45–1.66)

0.657

yes

57

25

38

16

body mass index > 30

no

156

76

0.68 (0.18–2.60)

0.577

161

77

0.78 (0.20–3.04)

0.725

yes

9

3

8

3

smoking during pregnancy

no

122

49

1.87 (1.07–3.27)

0.029

128

47

2.14 (1.24–3.70)

0.006

yes

44

33

47

37

paternal unemployment

no

145

61

2.26 (1.15–4.48)

0.019

158

71

1.70 (0.78–3.69)

0.179

yes

21

20

17

13

low paternal education^**

no

138

55

2.41 (1.27–4.58)

0.007

123

48

1.69 (0.97–2.94)

0.062

yes

25

24

50

33