Table 2 Information about the children in the case and control groups

Birth weight (kg)

Lower than 2.5

(7.8) 8

(2) 2

0.056

2.5 to 4

(92.2) 94

(96) 98

More than 4

(0) 0

(2) 2

Birth age (weeks)

Lower than 37

(4.9) 5

(2) 2

0.514

37 to 42

(93.1) 95

(96) 98

More than 42

(2) 2

(2) 2

Order of birth

First

(57.8) 59

(64.7) 66

0.729

second

(30.4) 31

(24.5) 25

Third

(7.8) 8

(7.8) 8

Forth

(2.9) 3

(2.9) 3

fifth

(1) 1

(0) 0