Table 2 Subgroup analyses of the association between cesarean section and asthma

Type of CS

 Elective CS

13

1.18

1.11–1.25

 < 0.001

71.4

 Emergency CS

13

1.18

1.10–1.27

 < 0.001

83.3

Sex

 Female

3

1.26

1.13–1.42

 < 0.001

0

 Male

3

1.07

0.94–1.22

0.325

0

Continent

 Asia

4

1.17

0.97–1.42

0.102

81.3

 Europe

23

1.20

1.15–1.26

 < 0.001

70.4

 North America

5

1.15

1.11–1.19

 < 0.001

0

 Oceania

3

1.06

1.02–1.11

0.008

0

Atopic asthma

6

1.14

1.11–1.18

 < 0.001

0

Persistent asthma

3

1.15

0.99–1.33

0.063

65.3

Cohort design

 Prospective cohort

13

1.19

1.11–1.28

 < 0.001

40.4

 Retrospective cohort

22

1.17

1.11–1.23

 < 0.001

86.9