Table 1 Associations of demographic, pregnancy, and birth characteristics with hepatoblastoma adjusted for birth weight, birth year, and sex — Minnesota, 1982–2004

Birth characteristics

 Birth weight (g)

>2000

7606 (98.0)

28 (77.8)

1

1000–1999

124 (1.6)

4 (11.1)

9.15

3.09–27.1

<1000

31 (0.4)

4 (11.1)

25.6

7.70–85.0

 Sex

Female

3778 (48.5)

11 (30.6)

1

Male

4010 (51.5)

25 (69.4)

2.03

0.98–4.19

 Gestational age (weeks)^b

⩾37

6888 (91.6)

25 (69.4)

1

<37

631 (8.4)

11 (30.6)

1.70

0.56–5.13

 Size for gestational age

Small

252 (3.4)

0 (0.0)

—

Average

5427 (72.4)

29 (80.6)

—

Large

1821 (24.3)

7 (19.4)

—

 Multiple birth

No

7592 (97.5)

34 (94.4)

—

Yes

196 (2.5)

2 (5.6)

—

 Apgar score (1 min)

>7

5725 (76.6)

19 (52.8)

1

⩽7

1746 (23.4)

17 (47.2)

1.99

0.95–4.16

 Apgar score (5 min)

>7

7192 (96.4)

29 (80.6)

1

<7

265 (3.6)

7 (19.4)

2.24

0.70–7.11

 Assisted ventilation^c

No

4549 (98.3)

25 (86.2)

1

Yes

79 (1.7)

4 (13.8)

2.00

0.49–8.19

 Congenital abnormality

No

7676 (98.6)

31 (86.1)

1

Yes

112 (1.4)

5 (13.9)

5.87

1.88–18.3

Index pregnancy history

 Adequacy of prenatal care

Adequate

4530 (67.9)

24 (75.0)

1

Intermediate

1488 (22.3)

4 (12.5)

0.61

0.21–1.78

Inadequate

658 (9.9)

4 (12.5)

1.11

0.36–3.43

 Weight gain (pounds)^c

⩽24

1029 (26.7)

7 (25.9)

1

25–30

1295 (33.6)

10 (37.0)

1.36

0.48–3.83

>30

1526 (39.6)

10 (37.0)

1.40

0.48–4.07

 Intrauterine procedures

No

7271 (97.4)

32 (88.9)

1

Yes

193 (2.6)

4 (11.1)

2.39

0.68–8.41

 Induction of labor^c

No

3439 (71.6)

20 (66.7)

1

Yes

1361 (28.4)

10 (33.3)

1.32

0.60–2.93

 Type of delivery

Vaginal

6162 (82.0)

26 (72.2)

1

Caesarean section

1355 (18.0)

10 (27.8)

1.26

0.58–2.77

Maternal reproductive history

 Prior live births

0

3062 (39.9)

16 (44.4)

1

1–2

3799 (49.5)

11 (30.6)

0.62

0.28–1.35

⩾3

808 (10.5)

9 (25.0)

2.07

0.87–4.92

 Interval since last live birth (years)

No prior birth

3062 (40.1)

16 (44.4)

—

⩽3

2966 (38.9)

18 (50.0)

—

>3

1600 (21.0)

2 (5.6)

—

 Prior fetal losses

None

5919 (77.5)

30 (83.3)

1

Any

1717 (22.5)

6 (16.7)

0.60

0.24–1.49

Parental demographics

 Mother's age (years)

<25

2358 (30.3)

11 (30.6)

1.27

0.53–3.08

25–29

2708 (34.8)

10 (27.8)

1

⩾30

2722 (35.0)

15 (41.7)

1.31

0.57–3.01

 Father's age (years)

<30

3347 (47.5)

11 (33.3)

1

⩾30

3693 (52.5)

22 (66.7)

1.55

0.74–3.25

 Mother's race

White

7010 (90.9)

30 (83.3)

1

Non-white

700 (9.1)

6 (16.7)

1.56

0.63–3.89

 Mother's ethnicity^c

Non-Hispanic

4475 (96.5)

26 (86.7)

1

Hispanic

160 (3.5)

4 (13.3)

2.96

0.88–10.0

 Mother's birthplace

United States

7297 (93.8)

28 (77.8)

1

Elsewhere

485 (6.2)

8 (22.2)

3.55

1.51–8.32

 Father's race

White

6381 (92.5)

28 (87.5)

1

Nonwhite

521 (7.5)

4 (12.5)

1.44

0.49–4.29

 Father's ethnicity^c

Non-Hispanic

3996 (97.0)

24 (85.7)

1

Hispanic

125 (3.0)

4 (14.3)

4.18

1.22–14.3

 Mother's education (years)

<12

782 (10.6)

8 (22.9)

1.60

0.64–4.02

12

2706 (36.8)

14 (40.0)

1

>12

3867 (52.6)

13 (37.1)

0.61

0.28–1.32

 Father's education (years)

⩽12

2840 (44.2)

13 (43.3)

1

>12

3587 (55.8)

17 (56.7)

1.03

0.49–2.16