Foetal Exposure to Maternal Passive Smoking Is Associated with Childhood Asthma, Allergic Rhinitis, and Eczema

Table 1

Baseline characteristics of survey participants (𝑁=7393).

	Number	(%)
Age group, years
0-1	548	7.41
2–5	1433	19.38
6–10	2755	37.26
11–14	2657	35.94
Sex
Female	3554	48.07
Male	3839	51.93
Highest education level of parents
No and primary	660	9.05
Secondary and matriculation	5344	73.29
Tertiary	1288	17.66
Perinatal and postnatal problem
Yes	1044	14.12
No	6349	85.88
Current parent smoking
No	5404	73.10
Yes	1989	26.90
Total no. of household smokers
0	5298	71.66
1	1796	24.29
≥2	299	4.04
Family history of asthma
Yes	199	2.69
No	7194	97.31
Family history of atopy
Yes	612	8.28
No	6781	91.72
Respondents
Father	2127	28.77
Mother	5266	71.23
Birth place
Hong Kong	6556	88.68
Non-Hong Kong	837	11.32
Mode of delivery
Normal spontaneous delivery + other vaginal	5869	79.39
Cesarean delivery	1390	18.80
Missing	134	1.81
Current primary carer
Father	523	7.07
Mother	5755	77.84
Other	1115	15.08