Table 4 Crude and adjusted odds ratios (OR) and 95% confidence intervals for the association between birth weight, birth length or body mass index at age 4 and allergic diseases or sensitisation at 4 years in 2869 children (the BAMSE study).

	Sensitisation at 4 years, n = 388 (15%)			Eczema at 4 years, n = 624 (22%)			Rhinitis at 4 years, n = 341 (12%)
	n	Crude OR (95% CI)	Adjusted OR (95% CI)	n	Crude OR (95% CI)	Adjusted OR (95% CI)	n	Crude OR (95% CI)	Adjusted OR (95% CI)
Birth weight ⩽10th percentile, n = 288	37	0.92 (0.63 to 1.33)	1.06 (0.64 to 1.73)	56	0.86 (0.63 to 1.18)	0.98 (0.65 to 1.48)	35	1.05 (0.72 to 1.54)	1.25 (0.75 to 2.08)
Birth weight ⩾90th percentile, n = 292	32	0.79 (0.53 to 1.16)	0.66 (0.42 to 1.02)	66	1.05 (0.78 to 1.41)	0.99 (0.70 to 1.38)	37	1.09 (0.75 to 1.58)	1.17 (0.76 to 1.78)
Birth length ⩽10th percentile, n = 325	37	0.83 (0.57 to 1.21)	0.78 (0.48 to 1.25)	62	0.85 (0.63 to 1.14)	0.85 (0.58 to 1.24)	34	0.83 (0.56 to 1.22)	0.70 (0.42 to 1.16)
Birth length ⩾90th percentile, n = 414	63	1.15 (0.85 to 1.56)	1.22 (0.87 to 1.71)	94	1.06 (0.82 to 1.37)	1.05 (0.79 to 1.40)	45	0.86 (0.61 to 1.22)	0.84 (0.57 to 1.22)
BMI ⩽10th percentile, n = 279	32	0.79 (0.53 to 1.17)	0.87 (0.58 to 1.30)	53	0.83 (0.60 to 1.14)	0.84 (0.60 to 1.16)	41	1.31 (0.92 to 1.88)	1.37 (0.94 to 1.99)
BMI ⩾90th percentile, n = 273	25	0.64 (0.41 to 0.99)	0.71 (0.45 to 1.11)	61	1.02 (0.75 to 1.38)	0.99 (0.72 to 1.36)	27	0.83 (0.54 to 1.26)	0.82 (0.53 to 1.27)

BMI, body mass index at 4 years of age. Sensitisation to airborne allergens was defined as a positive Phadiatop (⩾0.35 kU/l). The multivariate logistic regression models contained birth weight, birth length, BMI, family history of allergy, maternal age, sex, exclusive breastfeeding, presence of older siblings, gestational age, maternal smoking and socio‐economic index.