Table 2 Participant health behaviours stratified by pregnancy intention

Age (n = 127,101)

 18–24

47,977

50.4% (49.9–50.8)

30.7% (30.4–31.0)

1.00 (ref)

1.00 (ref)

 25–34

64,683

43.8% (43.3–44.2)

54.8% (54.5–55.2)

2.06 (2.01–2.11)

1.82 (1.76–1.88)

 35–40

12,905

5.3% (5.1–5.6)

12.8% (12.6–13.1)

3.94 (3.76–4.13)

3.40 (3.19–3.62)

 41 + 

1536

0.5% (0.4–0.6)

1.6% (1.5–1.7)

5.29 (4.59–6.10)

4.60 (3.84–5.50)

 Question not answered

4081

-

-

-

-

BMI (n = 111,031)

 18.5–24.9 (Recommended)

46,739

45.6% (45.1–46.1)

40.2% (39.8–40.5)

1.00 (ref)

1.00 (ref)

  < 18.5 (Underweight)

3826

3.8% (3.6–4.0)

3.2% (3.1–3.4)

0.96 (0.90–1.02)

1.05 (0.97–1.13)

 25–29 (Overweight)

28,559

25.5% (25.1–25.9)

25.8% (25.5–26.2)

1.15 (1.12–1.19)

1.12 (1.08–1.16)

 30 + (Obese)

31,907

25.1% (24.7–25.5)

30.8% (30.4–31.1)

1.39 (1.35–1.44)

1.48 (1.42–1.55)

 Question not answered/BMI excluded

20,151

-

-

-

-

Smoking (n = 127,056)

 No

101,611

83.0% (82.7–83.3)

78.3% (78.0–78.6)

1.00 (ref)

1.00 (ref)

 Yes

25,445

17.0% (16.7–17.3)

21.7% (21.4–22.0)

1.35 (1.31–1.39)

1.87 (1.79–1.94)

 Question not answered

4126

-

-

-

-

Illicit or recreational drug use (n = 126,985)

 No

122,287

96.0% (95.8–96.1)

96.5% (96.4–96.6)

1.00 (ref)

1.00 (ref)

 Yes

4698

4.0% (3.9–4.2)

3.5% (3.4–3.6)

0.86 (0.81–0.92)

0.99 (0.92–1.08)

 Question not answered

4166

-

-

-

-

Alcohol consumption (n = 126,966)

 No

57,771

35.8% (35.3–36.2)

50.9% (50.5–51.2)

1.00 (ref)

1.00 (ref)

 Yes

69,195

64.2% (63.8–64.7)

49.1% (48.8–49.5)

0.54 (0.53–0.55)

0.58 (0.56–0.60)

 Question not answered

4185

-

-

-

-

Caffeine consumption (n = 126,820)

 No

25,919

19.1% (18.7–19.5)

21.2% (20.9–21.5)

1.00 (ref)

1.00 (ref)

 Yes

100,901

80.9% (80.5–81.3)

78.8% (78.5–79.1)

0.88 (0.85–0.91)

1.00 (0.96–1.04)

 Question not answered

4331

-

-

-

-

Weekly level of activity (n = 116,832)

 Less than 150 min of activity

49,071

40.9% (40.4–41.4)

42.6% (42.3–43.0)

1.00 (ref)

1.00 (ref)

 At least 150 min of moderate activity

50,813

44.4% (43.9–44.9)

43.0% (42.6–43.4)

0.93 (0.91–0.95)

0.91 (0.88–0.94)

 150 or more minutes of vigorous activity

16,948

14.7% (14.4–15.1)

14.4% (14.1–14.6)

0.94 (0.90–0.97)

0.94 (0.90–0.98)

 Question not answered

14,319

-

-

-

-

Daily consumption of five portions of fruit and vegetables (n = 115,793)

 No

36,589

32.5% (32.0–32.9)

31.1% (30.8–31.4)

1.00 (ref)

1.00 (ref)

 Yes

61,747

52.0% (51.5–52.5)

54.1% (53.7–54.4)

1.09 (1.06–1.12)

0.92 (0.89–0.95)

 Don’t know

17,463

15.5% (15.2–15.9)

14.8% (14.6–15.1)

1.00 (0.96–1.04)

1.05 (1.00–1.10)

 Question not answered

15,352

-

-

-

-

Folic acid supplementation (n = 99,362)

 No

68,033

90.8% (90.5–91.1)

56.0% (55.6–56.3)

1.00 (ref)

1.00 (ref)

 Yes

31,329

9.2% (8.9–9.5)

44.0% (43.7–44.4)

7.75 (7.45–8.06)

7.27 (6.97–7.59)

 Question not answered

31,789

-

-

-

-