TABLE 1

Characteristics of mothers and offspring who were included and excluded in the analyses^#

	Included	Excluded	p-value^¶
Subjects n	8915	3163
Maternal intake in pregnancy
Vitamin C mg·day⁻¹	82±35	74±36	<0.001
Vitamin E mg·day⁻¹	8.7±4.1	8.0±4.1	<0.001
Zinc mg·day⁻¹	8.3±2.4	7.8±2.4	<0.001
Selenium µg·day⁻¹	72.2±27.9	66.1±27.2	<0.001
Carotene µg·day⁻¹	2170±1176	2018±1175	<0.001
Fruits g·week⁻¹	671±390	557±392	<0.001
Vegetables g·week⁻¹	949±474	888±505	<0.001
Mother's age years	28.9±4.6	26.5±5.1	<0.001
Parity
0	45.5	42.8	<0.001
1	36.1	34.1
≥2	18.5	23.0
Sex of child
Male	51.1	52.2	0.28
Female	48.9	47.8
Multiple pregnancy
Singleton	97.6	97.1	0.14
Twin	2.4	2.9
Season of birth
Winter	16.2	15.8	0.65
Spring	26.9	26.7
Summer	30.1	31.3
Autumn	26.7	26.2
Breastfeeding duration
Never	21.2	35.4	<0.001
<3 months	31.5	32.9
3– <6 months	13.8	10.4
≥6 months	33.5	21.3
Mother's educational level
Certificate of Secondary Education	15.4	32.7	<0.001
Vocational	9.0	12.2
Ordinary level	35.4	32.6
Advanced level	25.1	15.6
Degree	15.1	6.8
Maternal ethnicity
White	98.1	95.5	<0.001
Non-White	1.9	4.5
Housing tenure
Owned/mortgaged	83.7	62.5	<0.001
Council rented	9.4	24.0
Noncouncil rented	6.9	13.5
Financial difficulties
Yes	17.1	22.9	<0.001
Maternal history of atopic diseases
Yes	68.3	68.9	0.62
Maternal anxiety score in pregnancy
0–9	21.3	16.9	<0.001
10–14	25.7	21.6
15–19	25.9	24.6
≥20	27.2	36.9
Maximum maternal tobacco exposure
None	26.5	17.5	<0.001
Passive only	46.0	36.1
1–9 cigarettes per day	8.0	9.5
10–19 cigarettes per day	11.3	19.9
≥20 cigarettes per day	8.2	17.1
Maternal paracetamol use during pregnancy
Yes	62.4	64.6	0.03
Maternal antibiotic use during pregnancy
Yes	16.1	14.5	0.04
Maternal vitamin/zinc supplement use during pregnancy
Yes	21.6	20.0	0.06
Maternal infections in pregnancy
Yes	45.8	46.9	0.27
Total energy intake kJ·day⁻¹	7260±1966	7162±2153	0.02
Maternal pre-pregnancy BMI
<18.50 kg·m⁻²	4.3	6.4	<0.001
18.50–24.99 kg·m⁻²	75.4	72.8
25.00–29.99 kg·m⁻²	15.1	14.8
≥30.00 kg·m⁻²	5.2	6.0
Birthweight
<2500 g	4.3	5.7	<0.001
2500–2999 g	13.8	15.2
3000–3499 g	35.4	36.6
3500–3999 g	33.2	30.8
≥4000 g	13.3	11.7
Gestational age weeks	39.5±1.8	39.4±1.8	0.03
Child's BMI at 7 years
<15.00 kg·m⁻²	28.1	29.6	0.51
15.00–17.49 kg·m⁻²	52.5	45.5
17.50–20.49 kg·m⁻²	15.2	19.3
≥20.50 kg·m⁻²	4.2	5.7
Maternal weight gain during pregnancy
Quartile 1	25.3	28.4	<0.001
Quartile 2	24.8	24.4
Quartile 3	25.6	22.0
Quartile 4	24.4	25.2

Data are presented as mean±sd or %, unless otherwise stated. BMI: body mass index. ^#: n=12 078; ^¶: Chi-squared tests were used for categorical variables, and t-tests and Wilcoxon tests were used for nonskewed- and skewed-distributed continuous variables, respectively.