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Table 1 Sociodemographic characteristics of women in the study (i)

From: Pregnancy, prison and perinatal outcomes in New South Wales, Australia: a retrospective cohort study using linked health data

  

Pregnancy in prison (ii)

  

Birth in prison

Birth out of prison

All pregnancy in prison (ii)

Prison controls (iii)

Community controls (iv)

  

n

%

n

%

n

%

n

%

P value (v)

n

%

P value (v)

Maternal age (years)

             

  Mean

    

26.5

27.2

 

30.0

<0.001

  Less than 20

6

6.1

11

5.4

17

5.6

108

8.7

0.0032

1540

3.9

<0.0001

  20–24

34

34.3

93

45.8

127

42.1

382

30.9

6045

15.4

  25–29

32

32.3

52

25.6

84

27.8

373

30.1

11472

29.1

  30–34

20

20.2

34

16.7

54

17.9

252

20.4

12798

32.5

  35 and over

7

7.1

13

6.4

20

6.6

119

9.6

7414

18.8

Parity

            

  None

30

30.3

57

28.1

87

28.8

410

33.1

0.5511

22061

56.0

<0.0001

  One

29

29.3

52

25.6

81

26.8

337

27.2

9764

24.8

  Two

17

17.2

38

18.7

55

18.2

207

16.7

4792

12.2

  Three

10

10.1

26

12.8

36

11.9

138

11.1

1705

4.3

  Four or more

13

13.1

30

14.8

43

14.2

146

11.8

1006

2.6

  Missing/not stated

0

0.0

0

0.0

0

0.0

0

0.0

 

39

  

Parous

 

69

69.7

146

71.9

215

71.2

828

66.9

0.1509

17267

43.9

<0.0001

Aboriginal/Torres Strait Islander

28

28.3

56

27.6

84

27.8

255

20.6

0.0068

863

2.2

<0.0001

Born in Australia

85

85.9

181

89.2

266

88.1

1091

88.1

0.9821

27598

70.1

<0.0001

Opioid Substitution Therapy (OST)

4

4.0

3

1.5

7

2.3

76

6.1

0.0034

30

0.1

<0.0001

Mental health admission

25

25.3

57

28.1

81

26.8

318

25.7

2345

6.0

Mental health admission and OST

41

41.4

108

53.2

149

49.3

510

41.2

136

0.3

Mental health admission or OST

70

70.7

168

82.8

237

78.5

904

73

0.0394

2511

6.4

<0.0001

Cigarettes/day (vi)

            

  None

23

23.2

29

14.3

52

17.2

287

23.2

0.0802

33699

85.6

<0.001

  1–10

16

16.2

49

24.1

65

21.5

311

25.1

2974

7.6

  >10

46

46.5

112

55.2

158

52.3

605

48.9

2428

6.2

  Missing/not stated

14

14.1

13

6.4

27

8.9

35

2.8

 

266

0.7

 

  Total

99

100.0

203

100.0

302

100.0

1238

100.0

 

39367

100.0

 

  Any smoking during pregnancy

76

76.8

174

85.7

250

82.8

960

77.5

0.0364

5813

14.8

<0.0001

Number of incarcerations (vii)

            

  1

35

35.4

67

33.0

102

33.8

711

57.4

<0.0001

n/a

n/a

 

  2

14

14.1

39

19.2

53

17.5

256

20.7

n/a

n/a

 

  3

11

11.1

35

17.2

46

15.2

111

9.0

n/a

n/a

 

  4

12

12.1

15

7.4

27

8.9

67

5.4

n/a

n/a

 

  5

5

5.1

8

3.9

13

4.3

33

2.7

n/a

n/a

 

  6–10

17

17.2

32

15.8

49

16.2

55

4.4

n/a

n/a

 

  11–20

5

5.1

7

3.4

12

4.0

5

0.4

 

n/a

n/a

 

Total N

 

99

100.0

203

100.0

302

100.0

1238

100.0

 

39367

100.0

 
  1. (i) For each group, singleton births and first births during the study period (index births) only.
  2. (ii) Births to women who were incarcerated for a minimum of five consecutive days during this pregnancy.
  3. (iii) Births to women were not incarcerated during this pregnancy, but were incarcerated at another time during the study period.
  4. (iv) A random 10% sample of births to women who were not incarcerated at all during the study period.
  5. (v) One-way ANOVA and Bonferroni tests were used to test for differences between study and control groups in the distribution of maternal age; chi-square tests were used to look for differences between groups for all other maternal demographics.
  6. (vi) Number of cigarettes smoked per day in the second half of pregnancy (from 20 weeks gestational age onwards).
  7. (vii) Number of incarcerations of at least five days’ duration, 1998 to 2006.
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BMC Pregnancy and Childbirth

ISSN: 1471-2393

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