Table 1 Characteristics women in the VeCaS cohort compared to national cohort (2015)

 All women (mean, SD)

30.4

(SD 4.5)

30.4

(SD 4.6)

p = 1.00

 Primiparous women (mean, SD)

28.8

(SD 4.3)

28.9

(SD 4.6)

p = 0.3174

   < 20 yr

27

0.6%

1125

0.9%

  20–24 yr

373

8.0%

12,072

9.4%

  25–29 yr

1575

33.9%

41,138

32.2%

  30–34 yr

1802

38.8%

49,438

38.7%

  35–39 yr

748

16.1%

20,885

16.3%

   ≥ 40 yr

115

2.5%

3160

2.5%

 P0

2184

47.1%

58,608

45.9%

χ² = 16.757, df = 2, p = 0.0002

 P1

1723

37.1%

46,010

36.0%

 P2+

733

15.8%

23,198

18.1%

 missing

0

2

 Dutch

3713

84.1%

96,589

75.6%

χ² = 171.058, df = 1, p < 0.0001

 Non-Dutch

700

15.7%

31,229

24.4%

 missing

227

 Higher

455

9.9%

30,149

23.7%

χ² = 499.183, df = 2, p < 0.0001

 Middle

2538

55.2%

55,949

44.0%

 Lower

1606

34.9%

41,146

32.3%

 missing

41

574

 Very high (> 2500)

226

4.9%

31,693

24.8%

χ² = 1463.241, df = 4, p < 0.0001

 High (1500–2500)

894

19.4%

32,707

25.6%

 Middle (1000–1500)

1498

32.4%

23,989

18.8%

 Low (500–1000)

1080

23.4%

21,991

17.2%

 very low (100–500)

919

19.9%

17,232

13.5%

 missing

23

206

 Low (< 18,5)

149

3.2%

 Normal (18,5-24,9)

2777

61.1%

 Overweight (25–29,9)

1088

23.9%

 Obesitas (≥30)

530

11.7%

 missing

96

 No

3676

81.0%

 Stopped in 1st trimester

367

8.1%

 Yes

497

10.9%

 missing

100