Table 5 Participant health behaviours stratified by duration of pregnancy planning

Age (n = 81,533)

 18–24

25,038

33.2% (32.7–33.6)

28.0% (27.6–28.5)

1.00 (ref)

1.00 (ref)

 25–34

44,732

55.9% (55.4–56.4)

53.8% (53.3–54.3)

1.14 (1.10–1.18)

1.27 (1.22–1.32)

 35–40

10,456

9.9% (9.6–10.2)

16.0% (15.6–16.4)

1.91 (1.83–2.00)

2.17 (2.05–2.30)

 41 + 

1307

1.0% (0.9–1.1)

2.2% (2.1–2.4)

2.53 (2.25–2.85)

2.88 (2.52–3.29)

 Question not answered

1340

-

-

-

-

BMI (n = 71,373)

 18.5–24.9 (Recommended)

28,662

42.4% (41.9–42.9)

37.7% (37.2–38.3)

1.00 (ref)

1.00 (ref)

  < 18.5 (Underweight)

2304

3.1% (2.9–3.3)

3.4% (3.2–3.5)

1.21 (1.11–1.32)

1.19 (1.09–1.29)

 25–29 (Overweight)

18,443

26.6% (26.1–27.0)

25.0% (24.6–25.5)

1.06 (1.02–1.10)

1.04 (1.00–1.08)

 30 + (Obese)

21,964

27.9 (27.5–28.4)

33.9% (33.4–34.4)

1.36 (1.32–1.41)

1.30 (1.24–1.36)

 Question not answered/BMI excluded

11,500

-

-

-

-

Smoking (n = 81,737)

 No

64,014

80.3% (79.9–80.6)

76.2% (75.8–76.6)

1.00 (ref)

1.00 (ref)

 Yes

17,723

19.7% (19.4–20.1)

23.8% (23.4–24.2)

1.27 (1.23–1.31)

1.25 (1.20–1.31)

 Question not answered

1136

-

-

-

-

Illicit or recreational drug use (n = 81,678)

 No

78,813

96.8% (96.6–96.9)

96.2% (96.0–96.4)

1.00 (ref)

1.00 (ref)

 Yes

2865

3.2% (3.1–3.4)

3.8% (3.6–4.0)

1.18 (1.09–1.27)

1.17 (1.07–1.28)

 Question not answered

1195

-

-

-

-

Alcohol consumption (n = 81,659)

 No

41,532

47.5% (47.1–48.0)

54.4% (53.9–54.9)

1.00 (ref)

1.00 (ref)

 Yes

40,127

52.5% (52.0–52.9)

45.6% (45.1–46.1)

0.76 (0.74–0.78)

0.74 (0.72–0.77)

 Question not answered

1214

-

-

-

-

Caffeine consumption (n = 81,568)

 No

17,278

20.4% (20.0–20.8)

22.0% (21.6–22.4)

1.00 (ref)

1.00 (ref)

 Yes

64,290

79.6% (79.2–80.0)

78.0% (77.6–78.4)

0.91 (0.88–0.94)

0.94 (0.90–0.98)

 Question not answered

1305

-

-

-

-

Weekly level of activity (n = 75,076)

 Less than 150 min of activity

32,002

42.9% (42.4–43.3)

42.4% (41.9–42.9)

1.00 (ref)

1.00 (ref)

 At least 150 min of moderate activity

32,291

43.1% (42.6–43.6)

43.0% (42.4–43.5)

1.01 (0.98–1.04)

1.03 (1.00–1.07)

 150 or more minutes of vigorous activity

10,783

14.1% (13.7–14.4)

14.7% (14.3–15.0)

1.05 (1.01–1.10)

1.08 (1.02–1.13)

 Question not answered

7797

-

-

-

-

Daily consumption of five portions of fruit and vegetables (n = 74,403)

 No

23,144

30.7% (30.2–31.1)

31.6% (31.1–32.1)

1.00 (ref)

1.00 (ref)

 Yes

40,216

54.8% (54.3–55.3)

53.2% (32.7–53.7)

0.94 (0.91–0.97)

0.93 (0.90–0.97)

 Don’t know

11,043

14.5% (14.2–14.9)

15.2% (14.8–15.6)

1.02 (0.97–1.06)

1.03 (0.98–1.09)

 Question not answered

8470

-

-

-

-

Folic acid supplementation (n = 63,541)

 No

35,561

54.9% (54.4–55.5)

57.1% (56.5–57.7)

1.00 (ref)

1.00 (ref)

 Yes

27,980

45.1% (44.5–45.6)

42.9% (42.3–43.5)

0.92 (0.89–0.95)

0.88 (0.85–0.91)

 Question not answered

19,332

-

-

-

-