Table 5 Occurrence rate (%) of participants with adverse pregnancy outcomes in each sublayer among the 4 pre-pregnancy BMI groups

 < 2

1/1 (100)

12/14 (85.7)

7/15 (46.7)

6/9 (66.7)

 ≥ 2–4

0/1 (0)

5//10 (50.0)

4/5 (80)

2/3 (66.7)

 ≥ 4–6

4/5 (80)

25/38 (65.8)

17/21 (81)

2/3 (66.7)

 ≥ 6–8

11/13 (84.6)

41/55 (74.5)

28/33 (84.8)

10/15 (66.7)

 ≥ 8–10

9/21 (42.9)

83/123 (67.5)

29/41 (69)

12/15 (80)

 ≥ 10–12

24/50 (48)

205/316 (64.7)

69/94 (73.4)

22/30 (73.3)

 ≥ 12–14

31/58 (53.4)

196/328 (59.8)

63/82 (76.8)

11/15 (73.3)

 ≥ 14–16

42/82 (50.6)

278/424 (65.6)

68/92 (73.1)

14/16 (87.5)

 ≥ 16–18

38/64 (59.4)

155/240 (64.6)

41/55 (74.5)

10/11 (90.9)

 ≥ 18–20

24/42 (57.1)

123/191 (64.4)

34/40 (85)

5/9 (55.6)

 ≥ 20–22

24/36 (66.7)

114/163 (69.5)

42/48 (87.5)

3/3 (100)

 ≥ 22–24

11/20 (55)

48/68 (69.6)

10/13 (76.9)

2/2 (100)

 ≥ 24–26

7/14 (50)

33/49 (67.3)

5/6 (83.3)

2/2 (100)

 ≥ 26–28

2/5 (40)

13/19 (68.4)

3/3 (100)

0/0 (0)

 ≥ 28

4/7 (57.1)

15/21 (71.4)

4/6 (66.7)

1/1 (100)