Table 1

Characteristics of the participating mother/child pairsa


Study groups
Variable
Infections (N = 190)
White blood cells (N = 86)
Lymphocyte subsets (N = 52)

Mother's age (yr)
28 (21–41)
29 (21–36)
29 (22–35)
Infant's age (d)
92 (75–123)
93 (76–112)
93 (76–112)


Percent
Percent
Percent

School yrs
≤ 13:50
14–16:24
>16:26
≤ 13:50
14–16:27
>16:23
≤ 13:43
14–16:30
>16:27
Smokingb
No:82
Yes:18

No:86
Yes:14

No:89
Yes:11

Alcoholb
No:82
Yes:18

No:83
Yes:17

No:77
Yes:23

Nursingc
Whole:81
Partial:19

Whole:84
Partial:16

Whole:91
Partial:9

Infant's sex
Girl:44
Boy:56

Girl:58
Boy:42

Girl:57
Boy:43

Vaccination
No:69
Yes:31

No:76
Yes:24

No:85
Yes:15

Resp. infection
No:72
Yes:28

No:71
Yes:29

No:78
Yes:22


aMother's and infant's age: median (range). WBCs were analyzed in a subgroup of 86 infants, and within this subgroup lymphocyte subsets were analyzed among 52 infants with enough blood left after WBC count analysis.

bDuring pregnancy.

cPartial nursing also includes no nursing.

Glynn et al. Environmental Health 2008 7:62   doi:10.1186/1476-069X-7-62